![Synthesis and Characterization of Zn Nanoparticles by using
Hetero-bicyclic Compound
V. Pushpanathana
and D. Suresh Kumarb
*
Supramolecular Research Laboratory, Department of Chemistry, Loyola College,
Chennai-600034, India
a
push.josephite@gmail.com, b
drdsklc@gmail.com
Keywords: Bicyclic compound, Zn nanoparticle, Benzil, Reducing and Stabilizing agent
Abstract: The 1:1 condensation reaction between benzil and tris(hydroxymethyl)aminomethane in
methanol yields a hetero bicyclic compound 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-
bicyclo[3.2.1]octan-2-ol. It was characterized by FT-IR, NMR (1
H and 13
C) spectroscopy and ESI
mass spectrometry. The structure was conclusively determined by X-ray diffractrometric analysis.
The structure shows a hetero bicyclic ring system. It consists of six membered morpholine and five
membered oxazolidine rings with free hydroxyl groups. This bicyclic compound was used as a
reducing and stabilizing agent to prepare zinc nanoparticles. The morphology and structure were
characterized by field emission scanning electron microscope (FE-SEM), powder X-ray diffraction
(XRD), and energy dispersive spectrum analysis (EDS).
Introduction
Nanoparticles have attracted much attention due to their unique optical, electronic,
magnetic, mechanical and chemical properties compared with those of the same bulk material.
These properties can be tuned by controlling their size and shape [1]. In the synthesis of
nanoparticles, the main problem is their stabilization and monitoring of their size and size
distribution. Many strategies have been employed for synthesizing metal nanoparticles including
hydrothermal synthesis [2], spray pyrolysis [3], sonochemical synthesis, microwave assisted
synthesis [4], chemical reduction in the presence of a stabilizing agent such as polymers or
surfactants, [5-7] electrochemical processes [8], sol-gel processes [9], and so forth. Zn nanoparticles
are the most important metal nanoparticles for such wide ranging applications as piezoelectric
transducers, gas sensors, transparent conductive films, light-emitting devices, photo detectors and
solar cell windows [10, 11]. Usually when metal nanoparticles are synthesized by chemical
methods, the metal ions reduced by the reducing agents [12] and protecting agents or phase transfer
agents are also added to stabilize the nanoparticles. Several types of toxic reducing agents
containing boron commonly have been employed to produce metal nanoparticles from inorganic
salts; the resulting metal nanoparticles are contaminated with borides. Hence investigation on the
synthesis of boride free metal nanoparticles has more significance especially for use in biological
and medical purposes. Here we report the novel synthesis of zinc nanoparticles using hetero
bicyclic compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol as a
reducing as well as stabilizing agents and their characterization by spectral techniques.
Experimental
Materials. Benzil, tris(hydroxymethyl)aminomethane and zinc(II) nitrate hexahydrate were
purchased from commercial sources and used as such. Solvents were of analytical grade and were
purified prior to use.
Analytical and physical measurements. Micro analytical (C, H, N) data were obtained with
a FLASH EA 1112 Series CHNS Analyzer. The IR spectra (with KBr pellets) were recorded in the
range of 400-4000 cm-1 on a JASCO FT/ IR-5300 FT-IR spectrometer. 1
H and 13
C NMR spectra were
recorded on a Bruker AVANCE III 400 MHz (AV400) multinuclear NMR spectrometer at 400
Advanced Materials Research Vol. 938 (2014) pp 3-8
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![MHz and 100 MHz, respectively. ESI mass spectra were obtained on a LCMS-2010A Shimadzu
spectrometer. The crystal data were collected on a Bruker axs kappa APEXII CCD Diffractometer.
Powder X-ray diffraction patterns were recorded on a Bruker D8-Advance diffractometer using
graphite monochromated CuKα1 (1.5406Å) and Kα2 (1.54439Å) radiations. The SEM image and
EDS spectrum of the zinc nanoparticles were examined using HITACHI S-4300SE/NFESEM and a
beam voltage of 20 kV.
Synthesis of hetero bicyclic compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-
aza-bicyclo[3.2.1]octan-2-ol (L1). To a hot solution of benzil (2.10 g, 10 mmol) in methanol,
tris(hydroxymethyl)aminomethane (1.21 g, 10 mmol) in methanol was added in drops and refluxed
for 4 h. The resultant clear solution was kept for a day to obtain colourless crystals. The crystals
were washed in cold methanol and dried in desiccator. Yield: 80%. Mp: 190◦
C (dec.). Elemental
analysis, Found (%): C, 68.95; H, 6.19; N, 4.33. Calc. for C18H19NO4 (%): C, 68.99; H, 6.11; N,
4.47. Mass spectrum (ESI): m/z 314 (MH+
), 336 (M+Na+
). 1
H-NMR (CD3OD) 3.47–3.80 (m, 4H),
4.03 (dd, 1H), 4.22 (d, 1H), 4.44 (d, 1H), 4.99 (s, 1H), 7.03–7.54 (m, 10H).13
C-NMR (CD3OD)
61.6, 65.48, 68.15, 70.07, 98.62, 98.62, 124.97, 126.86, 127.22, 128.09, 128.92, 130.96.
Scheme 1. Preparation of hetero-bicyclic compound (L1).
Synthesis of zinc nanoparticles. To a hot solution of reducing agent, 5-(hydroxymethyl)-
1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol (0.313 g, 1 mmol.) in methanol (30ml), a
solution of zinc(II) nitrate hexahydrate (1 mmol) in deionized water (10 ml) was added in drops for
30 min. The resultant solution was stirred and refluxed for 3 h under nitrogen atmosphere. On
keeping the solution overnight, the zinc nanoparticles were formed. These particles were separated
out by centrifugation, washed repeatedly with acetone to remove reducing agent and then dried at
room temperature.
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![Results and Discussion
In 2005, Giovenzana et al. reported that the reaction of benzil and
tris(hydroxymethyl)aminomethane in equimolar proportion yields colorless hetero-bicyclic
compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol (L1) instead
of L2 as shown in Scheme 1. The structure and stereochemistry of the crystalline product (L1) was
Fig. 1. (a) An ORTEP diagram and (b) Packing arrangement of crystal (L1)
conclusively determined by them using single crystal X-ray crystallography [13]. Our attempt to
sysnthesis L3 by stirring a dilute methanolic solution of benzil and
tris(hydroxymethyl)aminomethane, in 1:2 ratio and later refluxing, yielded the same crystalline
bicyclic compound (L1) instead of expected compound (L3). The obtained single crystal was
verified by X-ray crystallography. An ORTEP diagram of the crystal is shown in Fig. 1(a). The
crystal data are shown in Table 1.
Table 1. Crystallographic data for L1
Empirical formula
Formula weight
Temperature
Wavelength
Crystal system
Unit cell dimensions
a (Å)
b (Å)
c (Å)
α
β
γ
Volume
Z
Density (calculated)
Absorption coefficient
F(000)
Crystal size
Theta range for data collection
C18H19NO4
313.34
293 K
0.71073 Å
Monoclinic, Cc
15.5870 (9)
12.6447 (7)
7.9620 (4)
90.000(3) °
93.928 (2)°
90.000(3) °
1565.57 (15) Å3
4
1.329 Mg m−3
0.09 mm−1
664
0.3 × 0.3 × 0.2 mm
2.1–27.5°
The crystal structure of the hetero-bicyclic compound consists of six membered morpholine
and five membered oxazolidine rings fused together. The six membered ring has chair conformation
and the presence of two free hydroxyl groups increases the water solubility of the compound. The
two aromatic rings at C5 and C7 are trans to each other with a torsional angle of 53.47°. The crystal
packing consists of four bicyclic molecules. They are linked by N—H···O, O—H···O and O—
H···N weak interactions, generating a three dimensional-network as shown in Fig. 1(b). No
intramolecular hydrogen bonding is observed.
The FT-IR spectrum of the compound shows a broad band at 3400 cm-1
due to the presence
of alcoholic group. The absorption band at 2903 cm-1
is due to the N-H stretching vibration. The 1
H
NMR spectrum of the compound shows multiplets at 3.47-3.86 ppm corresponding to methylenic
protons. Aromatic protons resonate in the range 7.05-7.54 ppm. The alcoholic and secondary amine
protons are observed at 4.22 and 4.44 ppm, respectively.
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![nanoparticles. The formation of ZnO nanoparticles could be attributed to the trace amount of
dissolved oxygen present in the solvent as impurity [14]. The EDS shows the chemical purity and
stoichiometry of the nanoparticles. FE-SEM image and EDS spectrum of the Zn nanoparticles are
shown in Figs. 5(a) and (b), respectively.
Fig. 5. (a) FE-SEM image of Zn nanoparticles and (b) EDS spectrum
Conclusion
In this study, the bicyclic compound (L1) acts in a unique way both as reducing and
stabilizing agent for the synthesis of zinc nanoparticles. Despite several synthetic methods being
available, this method serves as a more simple and significant one for the synthesis of zinc
nanoparticles. The nanoparticles obtained are relatively pure and stable for several weeks.
Acknowledgements
The author (V. Pushpanathan) is thankful to UGC-NRC, School of Chemistry, University of
Hyderabad for the instrumentation facility. The authors are also thankful to Head, SAIF, IIT-
Madras for the XRD analysis.
References
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3799.
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8 Nanomaterials: Science, Technology and Applications](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-25-320.jpg)
![Hexamine Assisted Hydrothermal Synthesis of Eu3+
Activated
Na0.5La0.5MoO4 Microstructures: Synthesis, Structure and Morphological
Investigations
Rajagopalan Krishnan1, a
, Jagannathan Thirumalai1, b
,
Govindan Shanmuganathan1, c
, Itreesh Basha Shameem Banu1, d
,
Rathinam Chandramohan2, e
1
Department of Physics, B. S. Abdur Rahman University, Vandalur, Chennai, Tamilnadu, India.
2
Department of Physics, Sree Sevugan Annamalai College, Devakottai, Tamilnadu, India.
a
krishnanrphy@gmail.com, b
thirumalaijg@gmail.com (corresponding author),
c
shangovinth@gmail.com, d
shameembanu@bsauniv.ac.in, e
rathinam.chandramohan@gmail.com,
Keywords: Hydrothermal route, hexamine, self-assembly, photoluminescence
Abstract
Highly uniform and self-assembled spheroid-like microstructures of Na0.5La0.5MoO4:Eu3+
were successfully synthesized by hexamine assisted hydrothermal route at 180 °C for 24 hours with
neutral pH (7~8). Scanning electron microscope, X-ray diffraction pattern and energy dispersive X-
ray analysis were used to characterize the morphology, crystal structure, size, and elements of the
particles. It is found that, the particle size was well-controlled by increasing the molar concentration
of the chelating agent hexamine. While, irradiating at 395 nm UV light, the emission spectra of
micro-spheres shows remarkable characteristic dominance of red emission which is attributed to the
transition 5
D0→7
F2. Furthermore, the synthesized homogeneous and well-crystallized
Na0.5La0.5MoO4:Eu3+
microstructures will serve as an excellent phosphor candidate to produce high-
quality luminescence for display devices in future.
1. Introduction
Self-aggregated 3D micro/nanostructures with well controllable size and morphology have
attracted and become hot research topic of investigation. In the recent years, momentous
advancement has been made in the self-organization of hierarchical architectures for the fabrication
of micro/nanostructured materials and devices. Especially, monodispersed and self-organized three
dimensional superstructures and their size dependent properties have initiated worldwide intense
research due to their potential applications in fluorescent probes for biological staining, high-
performance luminescence device, highly efficient catalysts, opto-electronic device, and biomedical
applications based on their novel electronic and optical properties [1,2]. For example, Sheaf-like
orthorhombic Gd2(MoO4)3:Eu3+
nanostructures [3], rugby-like Na0.5La0.5MoO4:Eu3+
micro
structures [4], ordered nanorods composed of nanoparticles of NaLa(MoO4)2:Eu3+
[5], self-
assembled 3D flower-like NaY(MoO4)2:Eu3+
structures [6], etc., Therefore, the development of a
reliable and convenient synthetic route that can control the shape of nanostructures under ambient
conditions must be important for lighting and display applications. Among the conventional
solution based technique, hydrothermal route has lot of advantages which include simplicity,
convenience and its being an innovative route to synthesis various micro/nanostructures at a
relatively low temperature.
In recent years, lanthanide-doped luminescent micro/nano-sized particles have received
much attention for their wide applications on high-resolution displays, integrated optical systems,
and substitute for organic dyes, solid-state lasers, and especially biological labels. In particular,
Advanced Materials Research Vol. 938 (2014) pp 9-13
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![scheelite-type crystal structures of molybdates and tungstates doped with different rare earth ions
has been extensively studied in the field of opto-electronics and laser technology due to 4f
electronic configurations of rare earth ions [5]. The compound Na0.5La0.5MoO4 possesses a
scheelite-type crystal structure in which Mo6+
are populated in the centers of tetrahedral symmetry
and Na+
and La3+
are populated in the dodecahedral sites in the tetrahedral symmetry [7]. In this
paper, we have investigated controlled synthesis of three dimensional hierarchical micro-
architectures of Na0.5La0.5MoO4:Eu3+
by hexamine-assisted facile hydrothermal route. To
investigate the effect of the chelating reagent on the fabrication of 3D micro/nanostructures,
different molar concentration of hexamine was used in the reaction process.
2. Experimental procedure
All reagents were analytical grade and were used without further purification in the
experiment. In a typical synthesis, first La2O3 and Eu2O3 dissolved in a stoichiometric amount of
diluted hydrochloric acid, and transparent solutions were prepared using appropriate molar
concentrations and stirred vigorously for 15 min. The stoichiometric amount of Na2MoO4 was
dissolved in 30 mL of double-distilled water under vigorous stirring. Then, the two solutions were
carefully mixed; a white colloidal precipitate appeared immediately. This is followed by 0.5-1.0
mM of hexamethylenetetramine dissolved in 15 mL of double-distilled water and carefully added to
the white colloidal solution. The obtained pH value of the mixed solution was adjusted to 7-8 by
adding NaOH solution. After stirring for about 30 h, the resultant solution was transferred into a
closed teflon-lined vessel sealed, and heated at the temperature of 180–200°C for approximately 24
h. When the vessel had cooled to room temperature, the solid product was collected by filtration,
and washed with deionized water to remove the residue by centrifugation at 1500 rpm for 30 min to
produce a white precipitate, and then dried at 70°C.
3. Result and discussion
3.1 Structural and morphological investigation
Fig. 1 shows the X-ray diffraction pattern of Na0.5La0.5MoO4: Eu3+
samples prepared with
different molar concentrations of hexamine, 0.5 mM (A1), 1.0 mM (A2) using the hydrothermal
route at 180 °C for 24 hrs. It indicates all the peaks in XRD pattern are good in agreement with the
standard JCPDS card No. 79-2243 of Na0.5La0.5MoO4. A good crystalline products are successfully
synthesized and their strongest intensity peaks are at 2θ =28.05 and 45.90 degrees corresponds to
112 and 204 planes, respectively. XRD pattern reveals that they belong to tetragonal phase with
scheelite structure with space group I41/a. No other additional peaks of impurity phases were
detected.
Fig. 1 X-ray diffraction (XRD) patterns of Na0.5La0.5MoO4:Eu3+
of spheroid-like micro-
structures prepared by modulating the amount of hexamine at (A1) 0.5 (A2) 1.0, with a fixed
[La3+
/Eu3+
] concentration.
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![Fig. 2 Low –magnification SEM images of Na0.5La0.5MoO4:Eu3+
3D structures prepared by
hydrothermal route at 180°C for 24 h with different molar ratio of hexamine: 0.1 (a), 0.5 (b),
1.0 (c), respectively. (d) Energy dispersive X-ray spectrum (EDX) of Na0.5La0.5MoO4:Eu3+
prepared with 1.0 mM of hexamine.
The morphology of Na0.5La0.5MoO4:Eu3+
hierarchical 3D structures in the presence of
hexamethylenetetramine (hexamine) as surface capping agent were studied. Electron microscopy
(SEM) images of the sample prepared using the typical procedure is shown in
Fig. 2. The effect of surfactant (0.1 mM, 0.5mM, 1.0mM) on the morphology of
Na0.5La0.5MoO4:Eu3+
was investigated by modulating the molar ratio of hexamine with a fixed
[La3+
/Eu3+
] and MoO4
2-
. It was found that the molar ratio of hexamine introduced to the reaction
system had a crucial effect on the morphology and size distribution of the final products. It is
observed that the molar ratio of hexamine was lower than 0.5 mM; 2D nanosheets are joined to
form irregular sphere-like morphology and it became the predominated product (Fig. 2a). The SEM
image (Fig. 2b) of Na0.5La0.5MoO4:Eu3+
obtained with 0.5 mM of hexamine shows that nanosheets
were further stacked together to form spherical morphology with an average of 2.0 µm in diameter.
The molar ratio of hexamine was increased to 1.0 mM, the corresponding SEM images (Fig. 2c)
shows nearly uniform spheroids with an average diameter of 3.40 µm. From the above
morphological investigation the addition of hexamine into very small amount, can dramatically
affect the final morphology of the products. The corresponding SEM images (Fig. 2 (a-c)) clearly
indicate the increase of particle size of Na0.5La0.5MoO4:Eu3+
. Further, the EDX (Fig. 2d) spectrum
confirms the presence of elements La, Eu, Na, Mo, and O in the product.
3.2 Photoluminescence properties
A moderately resolved PL emission spectra (Fig. 3), shows the Stark splitting pattern of
5
D0→7
FJ (where J = 1, 2, 3, 4) intra-configurational f–f electronic transitions of Eu3+
activated
Na0.5La0.5MoO4 microstructures. The emission (λex =395 nm) spectra of the Na0.5La0.5MoO4:Eu3+
prepared with 1.0 mM concentration were recorded within the range from 575 to 700 nm at room
temperature. Upon excitation with 395 nm UV irradiation, the emission spectra were dominated by
the hypersensitive red emission [3], showing a transition 5
D0→7
F2 (due to electric dipole transition)
stronger than 5
D0→7
F1 (magnetic dipole). The presence of electric dipole transition confirmed that
Eu3+
ions were located at sites without inversion symmetry (C3v symmetry). The other transitions
5
D0→7
F1,
5
D0→7
F3 and 5
D0→7
F4 were relatively very weak. The presence of strong luminescent
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![intensity indicated the perfection of the microstructures of Na0.5La0.5MoO4:Eu3+
and good
crystallization. In the present case, Na0.5La0.5MoO4:Eu3+
belongs to scheelite tetragonal structure
and the transition of Eu3+
shows major lines with a bright red emission. These results may be
important in the fabrication of high-resolution optical detectors and high-definition luminescent
displays.
Fig. 3 Photoluminescence emission spectra (λex = 395 nm) of Na0.5La0.5MoO4: Eu3+
samples
prepared with 1.0 mM hexamine concentration.
4. Conclusion
The red phosphor Na0.5La0.5MoO4: Eu3+
has been successfully synthesized via a facile and
mild hydrothermal route employing hexamine as a surfactant. The phase of the crystal structure was
identified by X-ray diffraction pattern. The SEM image shows that when the molar concentration of
hexamine increases from 0.5mM to 1.0 mM, the size of the particles increases. The
photoluminescence properties of Na0.5La0.5MoO4:Eu3+
were thoroughly investigated. The material
shows bright red emission from the hypersensitive 5
D0→7
F2 transition (615 nm) at 395 nm UV
excitation. In this case, optimal molar concentration of hexamine for Na0.5La0.5MoO4:Eu3+
matrix in
hydrothermal route is 1.0 mM. We hope this material has potential application on the display device
and is an efficient red phosphor candidate in the high quality luminescence display device for the
future.
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3D architectures: Synthesis characterization and its luminescence behavior, J. Nanostructure
in Chem., 3 (2013) 14-19.
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[6] Y. Huang, L. Zhou, L. Yang, Z. Tang, Self-assembled 3D flower-like NaY(MoO4)2:Eu3+
microarchitectures: hydrothermal synthesis, formation mechanism and luminescence
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[7] G.M. Kuz’micheva, V.B. Rybakov, V.L. Panyutin, E.V. Zharikov, K.A. Subbotin,
Symmetry of (Na0.5R0.5)MO4Crystals (R = Gd, La; M = W, Mo), Rus. J. Inorg. Chem. 55
(2010)1448-1453.
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![Effect of Surfactants on Structural and Dielectric Properties of
Cobalt Ferrite
Hemal Khatri1, a
, Packiaraj G.2, b
, and R. B. Jotania3, c
1 ,2,3
Department of Physics, University School of sciences, Gujarat University,
Ahmedabad – 380009, Gujarat, INDIA.
a
hhk008@gmail.com, b
packiaraj33@gmail.com, c
rbjotania@gmail.com
Keywords: Spinel ferrite, Cobalt ferrites, Co-precipitation Method, Surfactants, XRD
Abstract. Cobalt ferrite (Cofe2o4) particles were synthesized with and without presence of
surfactants using a co-precipitation method. Three surfactants Cetyl Tri methyl Ammonium
Bromide (CTAB-cationic), Sodium dodecylbenzenesulphonate (anionic), Triton X-100 (nonionic),
were used and investigate their effects on the structural and dielectric properties of
CoFe2O4 particles. The ferrite precursors were first pre calcined in a muffle furnace at 500°C and
then calcined at 950°
C. Structural, dielectric and magnetic properties of prepared particles were
investigated using X-ray powder diffraction, Dielectric and Low field ac magnetic susceptibility
measurement. Phase purity of prepared samples was confirmed by X-ray diffraction. The sample
with surfactant Triton X-100 shows the highest values of dielectric constant at low frequency.
Introduction
The spinel ferrites are generally described by formulae such as MxFe3-xO4 in which M represents a
transition metal [1]. Spinel ferrites have been investigated in recent years because of their high
electrical resistivity, chemical stability, mechanical hardness and reasonable cost [2-5]. Most
fascinating applications include antenna rod, transformer core, recording head, loading coil,
memory and microwave devices, etc [6]. These are also useful to prevent and eliminate radio
frequency interference to audio systems. Inverse spinel ferrites such as CoFe2O4, NiFe2O4,
MnFe2O4 and CuFe2O4 showed ferrimagnetisms with high coercivity and moderate magnetization.
CoFe2O4 is suitable material for developing new technologies in the areas of strategic importance
[7-9].
CoFe2O4, are well known hard magnetic materials with very high cubic magneto crystalline
anisotropy, high coercivity, and moderate saturation magnetization. These properties make it a
promising material for high density magnetic storage. The systems made up of nanoparticles are
intensively studied both theoretically and practically due to their electric, dielectric and magnetic
properties that are sensibly different from those of the bulk materials and their possible applications
in various fields [10]. These nanoparticles can be obtained by precipitation of metallic salts in
different media as polymers, organic acid or alcohol, sugars etc., to ensure their colloidal stability,
physiological condition and enhanced functionality. The size range depends on the precursors,
surfactants and salts [11].
Surfactants (cationic, anionic and non-ionic) are amphiphilic materials containing a polar long-
chain hydrocarbon “tail” and a polar, usually ionic “head” [12]. It can play an important role in
synthesizing the material in different interesting morphologies. They may be used to control the
size, shape and agglomeration among the particles. The coating of Surfactant on ferrite particles
serves as a protective layer that prevents agglomeration of the particles, the oxidation of these
nanoparticles from the atmospheric oxygen and minimizes the direct exposure of the ferrite surface
to the biological environment [13, 14]. Ferrites have been synthesized using various methods such
as solid state reaction, co-precipitation, micro emulsion, solvothermal, mechanosynthesis
hydrothermal, sol–gel and combustion techniques. Co-precipitation method is a simple route to
prepare fine, nano-crystallized, high-purity and homogeneous powders of single or multi-
component oxides [15, 16].
Advanced Materials Research Vol. 938 (2014) pp 14-18
© (2014) Trans Tech Publications, Switzerland
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![D=
.
(1)
Where, λ is wavelength of X-ray used in Ǻ, β is FWHM in radian and θ is Bragg angle.
The intensities of peaks for the sample with CTAB are high, which indicate higher crystallinity [17]
and slight increase in crystallite size is also observed with cationic surfactant CTAB. With anionic
(Sodium dodecylbenzenesulphonate) and nonionic (Triton X-100) surfactants crystallite size is
decreased. Non-ionic surfactant Triton x-100 is not ionized in water and has good stability, which
leads to a better morphology of nanocrystalline than that of nanocrystalline prepared with other
ionic surfactant. Therefore, the nanocrystalline prepared with Triton x-100 is much smaller, which
indicates that molecular weight has great influence on the crystallite size.
Fig. 1. XRD patterns of CoFe2O4 (a) Standard CoFe2O4 (b) Pure CoFe2O4 (c) CoFe2O4 with surfactant CTAB (d)
CoFe2O4 with surfactant Sodium dodecylbenzenesulphonate (e) CoFe2O4 with surfactant Triton X-100.
Table 1. d-spacing, FWHM and approximated Crystallite size
Dielectric Analysis. Fig. 2 shows the variation of dielectric constant (є’ and є”) and loss factor (tan
δ) as a function of frequency in the range 20 Hz to 2 MHz at room temperature for CoFe2O4
synthesized without surfactant and with different surfactants. It can be observed that all the samples
exhibit dielectric dispersion where both real and imaginary dielectric constant decreases rapidly
Sample Lattice constant (a) A° d(nm) FWHM XS (nm)
Pure CoFe2O4 8.3649 0.25146 0.147 77
CoFe2O4 with surfactant CTAB (cationic) 8.3772 0.25181 0.139 86
CoFe2O4 with surfactant
Sodium dodecylbenzene-sulphonate (anionic)
8.3744 0.25181 0.170 60
CoFe2O4 with surfactant
Triton X-100 (nonionic)
8.3780 0.25315 0.180 55
16 Nanomaterials: Science, Technology and Applications](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-33-320.jpg)
![with increasing frequency in low-frequency region while it approaches almost frequency
independent behaviour in high frequency region.
Fig. 2. Variation of dielectric constant (є’ and є”) and loss factor (tan δ) as a function of frequency
The polarization decreases with increase in frequency and then reaches a constant value due to the
fact that beyond a certain frequency of external field, the electron exchange between Fe2+
and Fe3+
cannot follow the alternating field. The large value of dielectric constant at lower frequency is due
to the predominance of species like Fe2+
ions, interfacial dislocations pile ups, oxygen vacancies,
grain boundary defects, etc. [18], However the decrease in dielectric constant with frequency is
natural because of the fact that any species contributing to polarizability lag behind the applied field
at higher and higher frequencies. The sample with surfactant Triton X-100 shows the highest values
of ε’ and ε’’ at low frequency. The increase in dielectric constant is due to decrease in grain size
with addition of Triton X-100. When grain size is decreased, the resistivity increases and hence
dielectric constant is increased.
Low field ac magnetic susceptibility. Low field ac magnetic susceptibility measurements on
prepared samples were carried out from room temperature to 600° C. The variations of magnetic
susceptibility with temperature for all the samples are shown in Fig. 3.
Fig. 3. Variation of ac magnetic susceptibility with Temperature
Advanced Materials Research Vol. 938 17](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-34-320.jpg)
![From temperature dependent magnetic susceptibility measurement, Single domain (SD) states were
observed for all the samples. In SD region, susceptibility increases and shows maxima at blocking
temperature and drops sharply at Curie point. It is clear from the Fig. 3 that the sample with Sodium
dodecylbenzenesulphonate surfactant showed high curie temperature and Triton X-100 added
sample showed minimum curie temperature.
Summary
Cobalt ferrite (Cofe2o4) particles synthesized using co-precipitation method. Prepared powder
characterized by XRD, Dielectric and Low field ac magnetic susceptibility measurement. XRD
analysis confirms formation of spinel ferrite phase. The decrease in grain size of the sample with
surfactant Triton X-100 shows the increase in dielectric constant.
Acknowledgement
This work was carried out under DRS-SAP program of UGC, Physics Department, Gujarat
University, Navrangpura, Ahmedabad 380 009, India.
References
[1] P.Tailhades et al. / Journal of Magnetism and Magnetic Materials 193 (1999) 148-151.
[2] R. Peelamedu, C. Grimes, D. Agrawal, R. Roy, J. Mater. Res. 18 (2003) 2292.
[3] A.K.M. Akther Hossain, M. Seki, T. Kawai, H. Tabata, J. Appl. Phys. 96 (2004) 1273.
[4] A. Goldman, Handbook of Modern Ferromagnetic Materials, Kulwer Academic Publishers,
Boston, USA, 1999.
[5] R. Valenzuela, Magnetic Ceramices, Cambridge University Press, Cambridge, 1994.
[6] V.S. Kumbhar et al. / Applied Surface Science 259 (2012) 39 – 43.
[7] R.Y. Hong, J.H. Li, X. Cao, S.Z. Zhang, G.Q. Di, H.Z. Li, D.G. Wei, J. Alloys Compd.
480 (2009) 947.
[8] R. Skomski, J. Phys.: Condens. Matter 15 (2003) R1.
[9] R.C. Kambale, P.A. Shaikh, N.S. Harale, V.A. Bilur, Y.D. Kolekar, C.H. Bhosale, K.Y.
Rajpure, J. Alloys Compd. 490 (2010) 568.
[10] I.H. Gul et al. / Journal of Magnetism and Magnetic Materials 320 (2008) 270–275.
[11] Digest Journal of Nanomaterials and Biostructures Vol. 6, No 4, October-December 2011, p.
1783-1791.
[12] A. Dominguez, A. Fernandez, N. Gonzalez, E. Igleslas and L. Montenegro, J. Chem. Ed. 74,
(1997) 1227.
[13] M. Ahmed, N. Okasha, et al., Journal of Alloys and Compounds 496 (2010) 345–350.
[14] Maaz et al. / Journal of Magnetism and Magnetic Materials 308 (2007) 289–295.
[15] Z. Zhong, et al., Powder Technology 155 (2005) 193–195.
[16] S. Briceno et al. /Journal of Magnetism and Magnetic Materials 324 (2012) 2926–2931.
[17] G.B. Ji et al. / Journal of Crystal Growth 270 (2004) 156–161.
[18] J.C. Maxwell, Electric and Magnetism, Oxford University Press, New York, vol. 2, p.828,
1973.
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![Modified Sol-gel production of Nano SDC20 Materials
S. Ramesh1, a
, K.C. James Raju2,b
and C. Vishnuvardhan Reddy3,c
1,2
School of Physics, University of Hyderabad, A.P., India
3
Department of Physics, Osmania University, Hyderabad, A.P., India
a
ramesh.ou1@gmail.com (corresponding author), b
kcjrsp@uohyd.ernet.ac.in,
c
reddycvv@osmania. ac.in
Keywords: Sol-gel process, Nano crystalline, XRD, Rietveld, TEM
Abstract. The production of high purity samarium doped ceria (SDC20, Sm0.2Ce0.8O2-δ)
nanopowders by modified sol-gel process using maltose and pectin as organic precursors. Around, 6
nm particle size can be obtained after calcination of the as synthesized (pre dried) gel at 500 o
C for
2 h. Rietveld refinement of Powder X-ray diffraction (XRD) patterns confirms the cubic structure
with single phase. Chemical composition of SDC20 is in good agreement with EDX measurements.
TEM and XRD analysis indicate the influence of sintering temperature on particle size, which
increases with increasing temperature. This modified sol-gel process is a non-toxic and
environmentally friendly for large-scale production of high purity nanopowders.
Introduction
In recent years, solid oxide fuel cells (SOFCs) have been attracting more attention because of their
ability to provide clean, green and high efficiency energy conversion [1]. However, major constraint
is the selection of materials for commercial SOFC, which are operated over a temperature of
1000 o
C. Performance of SOFC depends on electrolyte materials. SOFC electrolyte should have
high ionic conductivity, high chemical stability and high density etc., SOFC components made up
of nanopowders have advantage like an electrolyte component may exhibit a finer grain structure
and therefore a higher density of grain boundaries. Nanopartcles are active to heat transfer and have
higher rate of densification at lower sintering temperature as a result of high surface area. These
features may increase the oxygen ion mobility and therefore the ionic conductivity reducing ohmic
losses in an electrochemical cell [2].
There are many routes to synthesize SDC20 nanopowders such as sol-gel process [3], ethylene
glycol [4], and using ammonium nitrate [5]. Infact, it is important to use modified chemical method
over existing one to improve the SDC20 particles more easily and cost effective manner.
In the present study, a modified sol-gel process first proposed by Suci et al. [6] simple maltose
and pectin are used as chelating and gelating agents to produce high purity SDC20 nanopowders.
The obtained nanopowders are characterized using XRD, TEM, FE-SEM and EDX.
Experimental
SDC20 (Sm0.2Ce0.8O2-δ) composition was synthesized through modifies sol-gel process. Cerium
nitrate hexa hydrate Ce (NO3)3 6H2O,(Alfa acer, 99.8% purity) and samarium nitrate hexa hydrate
Sm (NO3)3 6H2O (Alfa acer, 99.8% purity) were used as starting materials. Samarium and cerium
nitrates were calculated based on stoichiometry, and weighed accurately. Commercial grade
maltose and pectin, Finar made, were used for gel preparation and mixed in mass ratio maltose:
pectin = 50:1. Maltose made from glucose and fructose units, also known as ordinary table sugar.
Pectin is present in ripe fruits and some vegetables. Pectin is widely used in food industry as
gelating agent. Pectin consists of 300 and 1000 monosaccharide units [6,7].
Advanced Materials Research Vol. 938 (2014) pp 19-23
© (2014) Trans Tech Publications, Switzerland
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![Fig. 1 Flow chart of modified Sol-gel process
As shown in Fig.1 step1: maltose and pectin in the mass ratio 50:1 are mixed with distilled water
in beaker until clear solution formation and labeled as a solution A. Step 2: cerium and samarium
nitrates are dissolved in distilled water, stirred properly to get clear solution and labeled as solution
B. The cationic concentration of solution B was controlled to 20 g L-1
of the final SDC20
composition. Step 3: solution A and solution B are mixed by dripping solution A into Solution B
under continuous stirring for 2 h. The aim of this treatment is to prevent agglomeration of the
constituent particles and to avoid solidification of the particles or raw granular formation during the
different stages of processing.
Maltose is made from one unit of α-glucose and β-fructose each. These two units in chains are
linked by a β-glycosidic bond, which is a covalent bond between two monosaccharides that
involves carbon C1 (anomeric) of the glucose and carbon C2 of the fructose. According to wang et
al. [7], the electronegative O atom present in glucose or fructose ring structure in C1-C5 or C1-C4
carbon atoms and in C1-C4 β-glycosidic link per unit formula of maltose gains a partial negative
charge, which enables the Ce3+
and Sm3+
cations. Ce3+
and Sm3+
cations are kept at a distance by
the large pectin molecule, those consist 300-1000 monosaccharide units that form gelation of matrix
structure hosting these cations. This is very important to control the large crystals formation during
the subsequent calcinations stage. This is very essential step to form nano crystalline SDC20 solid
solution. The homogeneous mixed solution was dried in a beaker at 80 o
C on magnetic stirrer warm
plate at constant stirring until the gel formation. The obtained gel was placed in a separate beaker
and dried it keeping on warm plate at 90 o
C for more than 20 hours until it became completely
gelatinized and results light yellow powders. Further, as synthesized powders were calcined at
500 o
C, 650 o
C, 750 o
C and 950 o
C for 2 hours. The resultant ash was ground in agate mortar to get
a fine homogeneous powder.
XRD patterns of the samples were obtained by BRUKER D8 ADVANCED using Cu Kα
radiation in the Bragg’s angle range of 20o
≤ 2θ ≤ 80o
at room temperature. Fullprof Rietveld
refinement software was used to analyze crystal structure. The calcined powders images were taken
using the scanning electron microscope ZEISS (FE-SEM) equipped with an energy dispersive X-ray
20 Nanomaterials: Science, Technology and Applications](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-37-320.jpg)
![spectrometer (EDX) analyzer. Transmission electron microscopy images were taken from FEI,
Technai20 G2 Stwin, G2083 model with Gatan CCD detector.
Results and discussion
XRD analysis
The Fig. 2 shows XRD patterns of SDC20. There are no extra peaks, when Sm doped into CeO2.
This confirms the formation of single phase and it contains only a cubic [8,9,10] structure with the
space groupFm3m . Fig. 3 shows the Rietveld refinement of SDC20 sample using cubic #225
Fm3m space group. The Rietveld refinement was carried by FULLPROF program [11]. The rietveld
parameters are shown in Table 1. The angular dependence of the peak full width at half maximum
(FWHM) was described by Caglioti’s formula. Peak shapes were described by the pseudo-Voigt
profile function. The background variation was described by a polynomial with six coefficients. All
atom positions are fixed by the symmetry of the Fm3m space group and were not refined. Rare earth
and alkaline earth cations are situated at the 4a site with the atomic coordinate (0 0 0) and oxygen is
at the 8c site corresponding to the (0.25 0.25 0.25) position.
Table 1. Crystallographic information
SDC 20
Structure: Cubic
Space group: Fm3m
500 o
C 750 o
C 950 o
C
Rp 5.04 5.45 4.99
Rwp 6.49 7.01 6.94
Rexp 7.45 7.40 6.74
GOF 0.87 0.94 0.97
Bragg R-factor 0.828 3.35 2.28
Rf factor 0.587 2.52 2.95
a(A°) 5.42125 (49) 5.42310 (25) 5.42484 (18)
V (A°3
) 159.330 (0.025) 159.494 (0.013) 159.647 (0.009)
Density (g/cm3) 7.176 7.166 7.162
Crystallite size (nm) 6 (2) 12.1(3) 49.5(2)
There is no difference in peak position between calcined and sintered samples except decrease in
broadening (peak width) of peaks; they became relatively sharper and narrow. This indicates the
grain growth at higher temperatures. Crystallite size, Dc of the calcined powders was calculated
from XRD line broadening (1 1 1) reflection using Scherrer’s formula
0.9
cos
c
D
λ
β θ
=
where λ is the wavelength of X-ray radiation, β is the full width at half maximum (FWHM) after
correcting the instrumental broadening, and θ is Bragg angle. The average crystallite was in the
range 6 - 49.2 nm when the powder calcined at different temperatures (figure 2, Table 1). Particle
size of calcined powder obtained from XRD is smaller than the average grain.
Advanced Materials Research Vol. 938 21](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-38-320.jpg)
![Conclusions
The high purity SDC20 composition was successfully prepared by modified sol-gel process using
maltose and pectin as organic precursors. Single cubic phase samarium doped ceria nano particles
were successfully synthesized. In this, modified sol-gel production process, homogeneous
distribution of metal ions and slow collapse of the carbohydrate structure during calcinations
prevent the rapid agglomeration of metal ions, which ensures small particle size of the product. The
electrical properties and sintering behavior of this material are currently being investigated and
reported in near future.
Acknowledgements
The author, Dr. S. Ramesh is greatly acknowledging the UGC for providing the financial assistance
under the DSKPDF scheme, Project No. F.4-2/2006(BSR)/13-389/2010 (BSR).
References
[1] H. Inaba and H.Tagawa, Ceria based solid electrolytes, Solid State Ionics, 83 (1996) 1-16.
[2] B.C.H. Steele, Appraisal of Ce1−yGdyO2−y/2 electrolytes for IT-SOFC operation at 500°C, Solid
State Ionics, 129 (2000) 95-110.
[3] J. Van Herle, T. Horta, T. Kawada, N. Sakai, H. Yokokaya, M.Dokiya, Oxalate
coprecipitation of doped ceria powder for tape casting, Ceramic International, 124 (1998)
229-241.
[4] S. Ramesh, K.C. James Raju, C.V. Reddy, Properties of Al2O3-Sm2O3-CeO2 electrolyte, Trans.
Nonferrous Met. Soc.China, 22 (2012) 1486-1494.
[5] P.L. Chen, I.W.Chen, Reactive Cerium (IV) Oxide Powders by the Homogeneous Precipitation
Method, J.American Ceramic Society, 76 (1993) 1577-1583.
[6] C. Suciua, L. Gageab, A.C. Hoffmanna, and M. Moceanb, Sol–gel production of zirconia
nanoparticles with a new organic precursor, Chemical Engineering Science, 61 (2006) 7831-
7835.
[7] Z. Wang, G.M. Kale, M. Ghadiri, Maltose and pectin assisted sol–gel production of
Ce0.8Gd 0.2O1.9 solid electrolyte nanopowders for solid oxide fuel cells, J. Mater. Chem., 21
(2011) 16494-16499.
[8] S. Omer, E.D. Wachsman, Jacob L. Jones, and J.C. Nino, Crystal Structure–Ionic
Conductivity Relationships in Doped Ceria Systems, J. Am. Ceram. Soc., 92 (2009) 2674-
2681.
[9] S. Ramesh, K.C. James Raju, Structural and Ionic conductivity studies of doped ceria
electrolyte, Electrochemical and Solid state letters, 15 (2012) B24-B26.
[10] S. Ramesh, K.C. James Raju, Preparation and characterization of Ce1-x(Gd0.5Pr0.5)xO2
electrolyte for IT-SOFCs, International Journal of Hydrogen Energy, 37(2012) 10311 -10317.
[11] J. Rodriguez-Carvajal, Recent advances in magnetic structure determination by neutron
powder diffraction, Physica B, 192 (1993) 55-69.
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![Effect of Heat treatment on Structural, Magnetic and Electric properties
of Z- type Barium Cobalt Hexaferrite powder
Neha Solanki1,a
, Packiaraj G2,b
and R. B. Jotania3,c
1,2,3
Department of Physics, University School of sciences, Gujarat University,
Ahmedabad – 380009, Gujarat, INDIA.
a
nehashah2385@gmail.com, b
packiaraj33@gmail.com, c
rbjotania@gmail.com
Key words: Z-type hexaferrite, sol-gel combustion technique, Structural analysis
Abstract. Z-type hexaferrite with composition Ba3Co2Fe24O41 has been synthesized using a sol-gel
auto combustion technique. The obtain combusted powder was sintered at 500 ᴼC and followed by
950 ᴼC for 4 hrs in a muffle furnace. The effect of different sintering temperature on crystal
structure, crystallite size, microstructure and dielectric properties were systematically investigated.
The prepared barium cobalt hexaferrite powder samples were characterized using different
experimental techniques like FTIR, XRD, AC conductivity and specific magnetization
measurements. It was observed from XRD results that heat treatment conditions play significant
role in the formation of hexaferrite phase. AC conductivity measurements were carried out at room
temperature in frequency range of 20Hz to 2MHz. All the samples show the frequency dependent
phenomena, i.e. the AC conductivity increases with increasing frequency.
Introduction
Among the planar hexagonal ferrites discovered between 1952 and 1956 by Philips were Y ferrite
(Ba2M2Fe12O22), W ferrite (BaM2Fe16O27) and Z ferrite (Ba3M2Fe24O41, Where M represents
divalent metal ions) [1, 2]. Among all hexaferrites Co2Z (M=cobalt (II)) has a much higher
permeability, dielectric constants, ferromagnetic resonance up to 1.5–3.4 GHz and a high thermal
stability due to its high Curie point of 400 ᴼC [3]. Co2Z is used as soft materials, in the manufacture
of multi-layer chip inductors (MLCIs), for high-frequency application such as LC filters and
megahertz–gigahertz (MHz–GHz) antenna [4]. Z-type hexaferrite possesses planar hexagonal
structure [5]. The unit cell is made up of S, R and T blocks and the divalent and trivalent metallic
ions are distributed among ten different lattice sites [6]. This structure is considered as a stack of six
kinds of blocks with stacking order is RSTSR*S*T*S* [7, 8] (Fig 1 (a, b)), where the asterisk
indicates the same R, S, and T stack but rotated 180° around the c-axis.
High temperature (1300 ᴼC) is requiring for sintering Z-type hexaferrite by the conventional
ceramic method [9]. The main disadvantage of this method is it produces coarser particles. However
several wet chemical methods such as hydrothermal synthesis [10], combustion synthesis [11, 12],
sol–gel technique [13], citrate method [14, 15] and chemical co-precipitation method [16] require
low sintering temperature. Sol-gel combustion synthesis route has some advantages like low
sintering temperature, good homogeneity, high product purity crystallinity, fine particle size,
narrow particle size distribution, less preparation time, inexpensive products [17, 18]. In present
paper, we report effect of heat treatment on structural, electric and magnetic properties of Z-type
Ba3Co2Fe24O41 hexaferrite powder prepared by sol-gel auto combustion technique.
Advanced Materials Research Vol. 938 (2014) pp 24-29
© (2014) Trans Tech Publications, Switzerland
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![Fig. 1. (a) Basic layers of a hexagonal ferrite and (b) crystal structure of Co2Z hexaferrite [8]
Experimental details
Synthesis of polycrystalline Ba3Co2Fe24O41 hexaferrite powder. Analytical grade Barium Nitrate
[Ba(NO3)2], Cobalt Nitrate [Co(NO3)2], Ferric Nitrate [Fe(NO3)2] and Citric Acid [C6H8O7·H2O]
were used as starting materials to prepare hexaferrite samples. The stoicheometric amount of metal
nitrates and citric acid (molar ratio 1:1) was first dissolved one by one in to deionized water and
kept on a magnetic stirrer under constant stirring. The Ammonia solution (30 % v/w) was slowly
added in mixed solution to adjust pH-7. The prepared solution was heated at 80 ᴼC on a hot plate
and stirred continuously till it transformed into a thick gel. At a proper temperature ignition started
and thick dried gel burnt in a self-propagating combustion to form a fluffy loose powder. Finally,
the as-burnt powder was calcined at 500 ᴼC and followed by 950 ᴼC for 4 hrs in a muffle furnace
then slowly cooled to room temperature to obtain Ba3Co2Fe24O41 hexaferrite powder.
Characterization. The effect of temperature on the formation of Ba3Co2Fe24O41 has been
investigated by FTIR and XRD analysis. X-ray diffraction data were recorded on a Rigaku powder
X-ray diffractometer using Cu-Kα radiation (λ =1.54056 Å) at 30.0 kV and 15.0mA in the region of
2θ = 20–80ᴼ. The crystalline phases were identified using X-ray diffraction. To confirm the
formation of Barium Cobalt ferrite and to understand the nature of the residual carbon in the
samples the FTIR spectra were recorded on a FTIR spectrometer (Bruker Tensor 27) at room
temperature using the KBr pellet method between wave number ranges 4000-400 cm-1
. The
dielectric measurements were carried out at room temperature in a frequency range of 20 Hz to
2MHz using inductance capacitance resistance meter bridge (An Agilent E4980A precision LCR
meter). Low field specific magnetization measurements were performed with a magnetic field of 10
Oe in the range from room temperature to 600 ᴼC for different calcined samples.
Results and Discussion:
XRD Analysis. Fig. 2 shows the XRD pattern of burnt powder and calcined (at 500 ᴼC and 950 ᴼC
for 4 hrs.) Ba3Co2Fe24O41 hexaferrite powder samples. All XRD peaks were indexed using powder-
X software. The XRD peaks position and intensity of diffraction lines were compared with
standered JCPDS-file no.19-0097. It is clear from figure 2 that as burnt powder and sample heated
500 ᴼC contain three different phases of CoFe2O4, α-Fe2O3, Ba3Fe2O6. At 950 ᴼC, well crystalline
hexaferrite phases of Ba3Co2Fe24O41, Ba2Co2Fe12O22 were obtained. The crystallinity was found to
enhanced in hexaferrite sample calcined at 950 ᴼC for 4 hrs. which is shown in Table. 1.
Advanced Materials Research Vol. 938 25](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-42-320.jpg)
![Fig. 3. FTIR spectra of Ba3Co2Fe24O41 as burnt sample and sintered at 5000
and 9500
C.
Low field specific magnetization measurement. Low field specific magnetisation measurements
on prepared samples were carried out from room temperature to 600 ᴼC. The variations of specific
magnetisation with temperature for all the samples are shown in Fig. 4. It is clear from Fig. 4 that
preheated sample followed by post calcined hexaferrite powder show low value of specific
magnetization compared to as burnt powder sample and preheated sample. However, Hopkinson
peaks are found to broaden for both as burnt as well as preheated samples. It may be attributed to a
wide distribution of the particles shape [19].
Fig. 4. Specific magnetization curve
AC conductivity measurements. AC conductivity of prepared samples was calculated from the
data of dielectric constant (ε′) and loss, tangent (tan δ) using the relation
Advanced Materials Research Vol. 938 27](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-44-320.jpg)
![σac = ε′ εo ω tan δ (1)
Where εo is the vacuum permittivity and ω = 2πf is the angular frequency.
Fig. 5. The variation of AC Conductivity with Log Frequency
The variations of AC conductivity (σac) with Log f for all three samples are shown in Fig. 5. It is
clear from Fig. 5 that AC conductivity of as burnt powder and preheated sample increase fast with
increase of frequency (> 500 Hz), while there is not much change in value of ac conductivity for
the sample calcined at 950 ᴼC (Preheated followed by calcination). The frequency dependence of
conductivity can be explained with the help of Maxwell Wagner two-layer model [20-21].
According to this theory, two layers are formed in dielectric structure. The first layer consists of
ferrite grains of fairly well conducting, which is separated by a thin layer of poorly conducting
substances, which forms the grain boundary. These grain boundaries are more active at lower
frequencies; which act as a hindrance for mobility of the charge carriers [22], hence the hopping
frequency of electron between Fe3+
and Fe2+
ion is less at lower frequencies. As the frequency of
the applied field increases, the conductive grains become more active by promoting the hopping of
electron between Fe3+ and Fe2+ ions, thereby increasing the hopping frequency. So, we observe a
gradual increase of conductivity with frequency [23, 24]. The linear increase in ac conductivity with
the frequency confirms the polaron type of conduction [25].
Summary
Z-type hexaferrite powder with composition Ba3Co2Fe24O41 synthesized using a sol-gel auto
combustion method. Prepared powder characterized using various FTIR, XRD, specific
magnetization measurement and electrical conductivity measurements. XRD analysis confirms
formation of hexaferrite phase in the sample preheated followed by 950 ᴼC calcinations. AC
1 2 3 4 5 6
0.0
1.0x10
-5
2.0x10
-5
3.0x10
-5
4.0x10
-5
5.0x10
-5
AC
Conductivity
(mho/cm)
Log F
As burnt Powder
Heated at 500
0
C
Preheated + Heated at 950
0
C
1.5 2.0 2.5 3.0 3.5 4.0
0.0
2.0x10
-7
4.0x10
-7
6.0x10
-7
8.0x10
-7
1.0x10
-6
AC
Conductivity
Log F
28 Nanomaterials: Science, Technology and Applications](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-45-320.jpg)
![conductivity found to increase with increase of frequency explained by using Maxwell-Wegner two
layer model.
Acknowledgement
This work was carried out under DRS-SAP programme of UGC, Physics Department, Gujarat
University, Navrangpura, Ahmedabad 380 009, India.
References
[1] J.J. Went, G.W. Rathenau, E.W. Gorter, G.W. Van Oosterhaut, Phil. Tech. Rev. 13 (1952)
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[3] J. Smit, H.P.J. Wijn, Ferrites, Philips Technical Library, Eindhoven, 1956, pp. 204–207.
[4] X.H. Wang, L.T. Li, S.Y. Su, Z.L. Gui, J. Am. Ceram. Soc. 88 (2005) 478–480.
[5] J.J. Xu, C.M. Yang, H.F. Zou, Y.H. Song, G.M. Gao, B.C. An, S.C. Gan, J. Magn. Magn.
Mater. 321 (2009) 3231–3235.
[6] G. Albanese, Journal De Physique, Colloque C1, supplyment au no 4, Tome 38, Avril 1977,
page C1-85.
[7] L. Jia, Y. Tang, H. Zhang, P. Deng, Y. Liu, B. Liu, Jpn. J. Appl. Phys. 49 (2010) 063001.
[8] K. Kamishima, J. Magn. Magn. Mater. 312 (2007) 228–233.
[9] M. R.Barati, J. Sol-Gel Sci. Technol. 52 (2009) 171–178.
[10] X. Jiao, D. Chen, Y. Hu, Mater. Res. Bull. 37 (2002) 1583.
[11] C. Hwang, J. Tsai, T. Huang, Mate. Chem. Phys., 110 (2005) 1-7.
[12] C. H. Peng, C. Hwang, S. Chen, Mater. Sci. Eng. B 107 (2004) 295.
[13] D. H. Chen, X. R. He, Mater. Res. Bull. 36 (2001)1369.
[14] M. Mouallem-bahout, S. Bertrand, O. Pena, J. Solid State Chem. 178 (2005) 1080.
[15] A. Verma, T. C. Goel, R. G. Mendiratta, J. Magn. Magn. Mater. 208 (2000) 13.
[16] Q. Chen, A. J Rondinone, B. C. Chakoumakos, J. Magn. Magn. Mater. 194 (1999) 1.
[17] B. L. Bischoff, M. A. Anderson, Chem. Mater. 7 (1995) 1772.
[18] C. C. Wang, J. Y. Ying, Chem. Mater. 11 (1999) 3113.
[19] V. J. árik, A. Grusková, J. Sláma, R. Dosoudil, A. González, G. Mendoza, Advances in
Electrical and Electronic Engineering (2011) pp 344-346.
[20] A. Katoch, A. Singh, International Journal of Enhanced Research in Science Technology &
Engineering 2 (2013) 1-7.
[21] A.K. Jonscher, Dielectric Relaxation in Solids, Chelsa Dielectrics, London, 1983.
[22] M. Hashim , Ceram. Int. 39 (2013) 1807–1819.
[23] M.A. El Hitti, J. Magn. Magn. Mater. 164 (1996) 187.
[24] A.M.Bhavikatti, International Journal of Engineering Science and Technology 2(11) ( 2010)
6532-6539.
[25] M. Penchal Reddy, W. Madhuri, G. Balakrishnaiah, N. Ramamanohar Reddy, K.V.
SivaKumar, V. R. K. Murthy, M. Hashim, Ceram. Int. 39(2013)1807–1819.
Advanced Materials Research Vol. 938 29](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-46-320.jpg)
![Kinetics of silver nanoparticle growth using DMF as reductant – Effect
of surfactants
Paramita Sarkar1,a
, Chithra Parameswaran1,b
, C Harish1,c
,
M Bhanu Chandra1,d
and A Nirmala Grace1,e
1
Centre for Nanotechnology Research, VIT University, Vellore-632014, TamilNadu, India
a
paramitasarkar2@gmail.com, b
chits.puthen@gmail.com, c
chevva.harish@gmail.com,
d
mbhanu.iiit@gmail.com, e
anirmalagrace@vit.ac.in
Keywords: Silver Nanoparticles, Kinetics, Surfactants, Surface Plasmon Resonance, FWHM
Abstract. Silver nanoparticles are synthesized using N,N dimethyl formamide (DMF) both as
reductant as well as solvent. The reaction is performed in the presence and absence of surfactants at
room temperature to know the effect of the same on the size and shape of the silver nanoparticles.
In this regard, two different surfactants viz. polyvinylpyrolidone (PVP) and cetyl trimethyl
ammonium bromide (CTAB) are used. The rate of the reaction and the formation kinetics is
continuously monitored by UV-vis spectroscopy at regular time intervals. The corresponding
change in plasmonic peaks and full width half maxima (FWHM) is studied in detail. The particle
size is determined using Mie plot.
Introduction
Optical properties of noble-metal nanoparticles are amazing, with varied applications in many fields
like optics and electronics due to their quantized motion of electrons known as plasmons. They give
a sharp absorbance for a certain wavelength in the UV-Vis spectroscopy, termed ‘surface plasmon
resonance’. The theory of surface plasmon band originates from the interaction of nanoparticles in
solution or in solid phase with a particular frequency domain. This is due to collective resonance of
conduction electrons specific of nanoparticles for their geometrical confinement effects of these free
electrons. This absorption is also referred to as ‘Mie Resonance’, after one of its most prominent
contributors Gustav Mie. The surface plasmonic band is observed for metallic nanoparticles bigger
than 2nm. Gold, silver and copper nanoparticles exhibit highly intense bands making them
prominent in this field. The position, shape and intensity of the absorption peak strongly depends on
dielectric constant of the surrounding medium and electronic interaction between stabilizing ligands
and the nanoparticle; these alter the electron density inside the particle and consequently their size,
shape and monodispersity [2]. This phenomenon, modelled successfully by Mie theory holds good
over more than 100 years. Several other models for the same are also appraised [3]. The optical
properties of metallic nanoparticles have been exploited in the industry for a wide range of
applications by their size and shape controlled synthesis.
Among the various nanomaterials, silver nanoparticles have fascinated a plethora of interest in the
scientific community due to their potential applications in areas such as nanoelectronics, optical
filters, electromagnetic interference shielding, and surface-enhanced Raman scattering. Among the
various solvents reported, DMF is one of the best candidates for the synthesis of silver nanoparticles
and hence used here. The polymer, PVP, is chosen in view of its applications in diverse fields like
catalysis, drug delivery, etc. PVP is a homopolymer having an individual unit containing an aprotic
polar imide group. The oxygen atoms of the imide group has a strong affinity to silver cations
supplying electrons to the silver cations, causing reduction and stabilization of the resulting silver
particles through surface adsorption of the PVP chain.
N
CH2 CH
n
[ ]
O
PVP
Advanced Materials Research Vol. 938 (2014) pp 30-35
© (2014) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMR.938.30](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-47-320.jpg)
![The Reaction mechanism N, N-dimethyl formamide (DMF) is one of the common organic
compounds used as a solvent for various reactions. The oxidation of DMF from hydrogen-water
mixtures generates hydrogen gas [7]. DMF acted as a potent reducing agent for the reduction of
Ni(IV) to Ni(II) in basic conditions, which shows that DMF could be used as an active reducing
agent under suitable conditions[8]. Liz-Marzan et al investigated the synthesis of silver
nanoparticles using DMF as solvent as well as reducing agent [9]. The mechanism of reducing
silver ions by DMF is
HCONMe2 + 2Ag+
+ H2O → 2Ag0
+ Me2NCOOH + 2H+
(1)
This mechanism is supported by a measured increase of conductivity as the reaction proceeds,
indicating that the larger Ag+
ions are progressively exchanged for the more mobile H+
ions. The
carbamic acid decomposes to carbon dioxide as explained below [7].
Me2NCOOH → CO2 + Me2NH (2)
A basic difference of this reaction from other reducing agents like alcohol is that the
reaction proceeds at a meaningful rate even at room temperature [10]. Although many studies have
been carried out in this area, some of the experimental details still remain unclear. Hence we have
chosen this system to study the nature and growth of Ag nanoparticles at various reaction
conditions. Several methods have been proposed. Here, chemical synthesis process is used, where
reduction is initiated by solvated electrons generated from ionizing radiation and is advantageous as
the reaction is carried out at room temperature and less time consuming. The reducing action of
DMF is already studied [5], but the kinetic analysis is yet to be done. Here, we emphasise the
kinetics of silver nanoparticles in the presence and absence of surfactants at room temperature. The
kinetics was studied by UV-Vis spectrometry. It is one of the many techniques to obtain
quantitative approximation of the plasmon peak, which is then exploited to precisely obtain particle
size with the aid of Mie Plot software which holds good for spherical nanoparticles. The FWHM
gives precise information on the particles size distribution and are evaluated manually from the
mid-value of recorded data. Also, theoretical curve fittings are employed to analyse the dependence
of the parameters on time and particle size. These are indicated by the black solid lines in the graphs
shown in following discussion. The regression coefficient (R2
) is a statistical parameter which
reveals the extent of dependence of the ordinate variable on the abscissa.
Materials and methods
Materials Silver nitrate (AgNO3), Polyvinylpyrrolidone (PVP), Cetyl trimethylammonium
bromide (CTAB) and N,N Dimethylformamide (DMF) were purchased from SD fine Chemicals.
All the synthesis was carried out in double distilled water.
Instrumentation UV-Vis Spectra are recorded using SpecordR
210 plus. The spectra were
plotted using Microcal Origin (Version 6.0), and particle size was determined theoretically by the
software MiePlot (Version 3.4.10).
Synthesis of silver nanoparticles
Synthesis of Ag nanopartricles using PVP 7mM AgNO3 and 20mM of PVP is added to
100ml of DMF under stirring at room temperature. The solution is kept under continuous stirring
for 15mins. After a period of time, a yellow colour is formed. UV-Vis spectrum is recorded every
2mins. The same experiment is carried out without PVP as well.
Synthesis of Ag nanoparticles using CTAB 7mM AgNO3 and 20mM of CTAB is added to
100ml of DMF under stirring at room temperature. The solution is kept under continuous stirring
for 15mins. After a period of time, a yellow colour is formed confirming nanoparticle formation.
UV-Vis spectrum was recorded every 2mins.
Advanced Materials Research Vol. 938 31](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-48-320.jpg)
![PVP and CTAB. The effect of surfactants on the size distribution of particles obtained is
investigated and it is found that CTAB is better than PVP in this regard. The distribution is very
wide in absence of surfactant, and narrower distribution is observed for CTAB, than PVP. Particle
of average size 33 nm is achieved with CTAB and for PVP it is 33.5nm. The reaction in presence of
CTAB did not occur at room temperature but in presence of a strong reductant NaBH4 (0.01M).
Hence, the actual function of CTAB in presence of DMF is yet to be explored.
References
[1] Asta Sileikaite, Judita Puiso, Igoris Prosycevas, Sigitas Tamulevicius, Material Science,(2009)
21-27
[2] Audrey Moores, Frederic Goettmann, New J.Chem., 30 (2006) 1121-1132
[3] Viktor Myroshnychenko, Jessica Rodroguez-Fernandez, Isabel Pastoriza-Santos, Alison
M.Funston, Carolina Novo, Paul Mulvaney, Luis M Liz-Marza, F. Javier Garcia de Abajo, Chem.
Soc.Rev., 37 (2008) 1792-1805
[4] Javed Ijaz Hussain, Sunil Kumar, Athar Adil Hashmi, Zaheer Khan, Adv. Mat. Lett. (2011) 188-
94
[5] Isabel Pastoriza Santos and Luis M. LizMarzan, Pure Appl. Chem., 72 (2000) 83-90
[6] Emil Roduner, Chem. Soc. Rev., 35 (2006) 583-592
[7] J.Y. Yu, S. Schreiner, L. Vaska, Inorg. Chim. Acta, (1990),170, 145.
[8] G.H. Hugar, S.T. Nandibewoor, Ind. J. Chem., (1993), 32A, 1056.
[9] I.P Santos, L.M. Liz Marzan, Langmuir, (2002), 18, 2888.
[10] H. Hirai, Y. Nakao, N. Toshima, N. J. Macromol. Sci. Chem., (1979), A13, 727.
Advanced Materials Research Vol. 938 35](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-52-320.jpg)
![Microstructure and adhesion properties of a-CN and Ti/a-CN
nanocomposite thin films prepared by hybrid ion beam deposition
technique
P. Vijai Bharathy1
*, Q.Yang2
, D.Nataraj3
1
Department of Physics, CBM College, Kovaipudur, Coimbatore
2
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
3
Thin film and Nanomaterials Lab, Department of Physics, Bharathiar University, Coimbatore, India
*(P.Vijai Bharathy) pvijay126@gmail.com
Keywords – Titanium, carbon nitride, nanocomposite thin film, XPS, nanomechanical properties,
Abstract
Carbon based materials have attracted much for its unique surface microstructure and
nanomechanical properties among researchers. In this study, the influence of microstructure on the
nanomechanical properties of thin carbon based films was studied in detail. For which amorphous
Carbon nitride (a-CN) and Titanium incorporated amorphous Carbon nitride (Ti/a-CN) thin films
were prepared with a thickness of less than 100 nm using hybrid ion beam deposition technique.
The incorporation of Ti into the a-CN matrix greatly modified the sp3
/sp2
hybridized bonding ratio
and it is reflected in the mechanical hardness of Ti/a-CN thin film. Most of the incorporated Ti
reacts with carbon and nitrogen to form TiN and TiCN phases respectively. On the other hand,
owing to the usage of energetic ion bombardment and the presence of TiN/TiCN phases in the
carbon nitride matrix, the Ti/a-CN nanocomposite film shows improved adhesion strength
compared to that of pure a-CN film. Overall the presence of hard metallic phase in the amorphous
carbon network alters the microstructure and improves the adhesion strength of a-CN films suitable
for protective coating applications.
Introduction
Amorphous hydrogenated carbon thin films have been attracting much attentions for its high
mechanical hardness, chemical inertness, high wear resistance and superior friction performance
suitable as protective coating material for biomedical devices and automotive engine parts [1-2].
Liu and Cohen [3] have theoretically predicted that a film with high hardness as that of diamond,
low compressibility and highly elastic fullerene like structures can be prepared by incorporating
nitrogen into the amorphous carbon matrix. After that numerous growth methods such as plasma
enhanced chemical vapour deposition (PECVD), vacuum cathodic arc method, magnetron
sputtering, ion beam assisted deposition and pulsed laser deposition [1,4,5] have been used to
incorporate nitrogen into diamond like carbon (DLC) matrix to form crystalline beta phase carbon
nitride (β-C3N4) thin film. Most of the research works were focused on altering the combination of
C-sp, C-sp2
and C-sp3
hybridized bonding fraction to increase the mechanical hardness of CN film
equal to that of diamond. Only few researchers have observed an increase in the lubrication effect,
low friction coefficient, increased biocompatibility and increased corrosion resistance [4-6] that too
by controlling the deposition conditions. However, most of the attempts lead to graphitic a-CN thin
film with poor adhesion strength and very low mechanical hardness with increase in nitrogen
fractions. Thus, apart from altering the existing deposition conditions, incorporating metal or non-
metal into the a-CN matrix is also an effective way to enhance the mechanical and tribological
properties of a-CN films.
In the present research work, a-CN thin film and titanium incorporated a-CN
nanocomposite thin film were deposited at room temperature using hybrid ion beam deposition
technique. To the best of our knowledge, no previous work has been reported on the fabrication of
pure a-CN and Ti/a-CN nanocomposite thin films using the present hybrid deposition method. Also
Advanced Materials Research Vol. 938 (2014) pp 36-39
© (2014) Trans Tech Publications, Switzerland
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![till now the role of titanium incorporation on the adhesion strength of a-CN film is not yet fully
understood. We focused mainly on understanding the chemical reactivity and the adhesion strength
of a-CN and Ti incorporated a-CN thin film.
Experimental Procedure
Amorphous Carbon nitride (a-CN) and Ti incorporated a-CN nanocomposite thin films were
deposited onto the Si (100) substrate by using hybrid ion beam deposition technique. This hybrid
deposition technique combines simultaneous deposition of carbon nitride film using ion beam
deposition and titanium incorporation using ion beam sputtering. The detail working mechanism of
the deposition system was explained elsewhere [7]. High purity methane and argon gases were
mixed in the ratio of 1:1 and introduced into end hall ion source 1. Along with the hydrocarbon ion
beam with ion energy 45 eV, high purity nitrogen gas (5 sccm) was introduced as back ground gas
to deposit amorphous carbon nitride thin film. Similarly for the deposition of Ti/a-CN
nanocomposite thin film, the hydrocarbon ion beam with ion energy of 45 eV mixed with nitrogen
gas was directed towards the substrate to deposit a-CN film, at the same time titanium was sputtered
by using Ar gas using another end-hall ion source II using the ion energy 45 eV. The Ti sputtering
was carried out with the negative target bias voltage of -800 V. The other deposition parameters
including the methane/argon, nitrogen gases ratio and ion beam energy from the ion sources were
fixed to constant. The substrate holder was placed at an angle of 45o
and rotated around its axis at a
constant rate of 3 rpm to enhance deposition uniformity. In order to maintain the substrate
temperature below 30o
C, separate substrate cooling was provided. The deposition time was altered
in accordance with the film thickness. The thickness of all the films was very close to 95 nm + 1 nm
as measured by surface profilometer.
The chemical composition and binding energies of a-CN and Ti/a-CN thin films were
determined using X-ray photoelectron spectroscopy using VG Microtech multilab 3000
spectrometer. The mechanical hardness and elastic modulus of the films were measured using
Nanoindenter [7,8]. The adhesion strength of the films was evaluated using scratch tester by
applying a ramping load range from 0.1 N to 20 N at a distance of 5 mm in 30 sec.
Results and Discussion
X-ray Photoelectron spectroscopic (XPS) Analysis
The chemical composition and bonding nature of pure a-CN and Ti/a-CN thin films were
studied using XPS analysis. The relative elemental concentration of titanium in Ti/a-CN film is 6.2
at.% for − 800 V biased voltage and the atomic percentage of nitrogen is ~7.2 at.% approximately.
Fig. 1 (a-b) shows the core-level C 1s and N 1s XPS spectra of as deposited pure a-CN thin film. It
shows that the C 1s spectrum was composed of two central carbon peaks corresponding to nitrogen
bonded C-sp3
(286.6 eV) and nitrogen bonded C-sp2
(285.5 eV) hybridized bonds. Additionally,
two more peaks were observed at 284.5 eV and 287.3 eV corresponding to sp2
(C-C) and N-sp1
C
atom, respectively. Similarly, Fig. 1b shows the de-convoluted N 1s core level XPS spectrum in-
between the binding energy 397 eV to 402 eV. The N 1s spectrum was fitted with different binding
energies like 398.6, 399.1, 400.2 and 401.9 eV which were attributed to nitrogen atoms bonded to
sp3
C, sp1
C, sp2
C and N or O atoms, respectively. All these binding energies of different C 1s and
N 1s peaks agree well with that of the previous literatures [7-9].
Fig. 1 (c-e) shows the deconvoluted C 1s, Ti 2p and N 1s core level XPS spectra of Ti/a-CN
thin film. Both the de-convoluted C 1s and N 1s spectra of a-CN and Ti/a-CN thin films do not
show much variation in the compositions of elemental bonding; however it shows a slight shift in
the peak positions. This may be due to the incorporation of Ti into the a-CN matrix. On the other
hand, many researchers suggested that based on the bonding fractions of sp3
C and sp2
C, the
overall properties of the carbon based films can be observed [8, 9]. Thus, the sp3
/sp2
ratios were
evaluated by using integrated areas of C 1s spectra for both a-CN and Ti/a-CN thin films. It was
found that the sp3
/sp2
ratio decreases by incorporating Ti and which is 0.543 for pure a-CN and
0.392 for Ti/a-CN film which directly implies an increase in C-sp2
content. This clearly indicates a
fact that by incorporating Ti, it starts to reacts with C atoms and thus breaks the C-C sp3
bonding to
form C-C sp2
bonding in Ti/a-CN nanocomposite thin film.
Advanced Materials Research Vol. 938 37](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-54-320.jpg)
![Magnus, he amuses a small circle of intimate friends; but his story, and
that of his sweet wife Rachel, as related by Mr. Farjeon, will increase
this friendly circle to a very considerable extent. The Baron ventures to
think that a good deal of the dialogue and of the descriptive writing is
unnecessary,—but Mr. Farjeon likes to give everyone plenty for their
money,—and, further, that the story would have gained by the loss of
what would have reduced the three volumes to two. But altogether, the
novel is "recommended" by the interested but disinterested
Baron de Book-Worms.
A VOTE OF THANKS.
By a Hard-up Journalist.
[A strange light has appeared on that part
of the surface of Mars not illuminated by
the sun. The Westminster Gazette of
August 2 asks the question, "Is Mars
signalling to us?"]
Oh, men of Mars, we thank you, your behaviour's really
kind!
(Forgive us if you've lately slipped somewhat out of
mind!)
For now the silly season's set in with all its "rot,"
You once more raise the question whether you exist or
not.
No doubt the good old topics will trot out yet again:—
"Is Flirting on the Increase?" "Is Marriage on the Wane?"
Big gooseberries as usual with sea-serpents will compete,
To help the British Press-man his columns to complete!](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-63-320.jpg)
![exceptional measures, and he resorted to
them with extreme regret. But if he were
asked for a justification of this motion, he
would refer hon. gentlemen to the Order
Book of the House of Commons."]
Gunner Harcourt, loquitur:—
Exceptional measures I hate,
I'd rather not always be battling;
The good old "Brown Bess" I prefer, I confess,
To a new (Parliamentary) Gatling.
To fight in the old-fashioned way,
Good temperedly, fairly, politely,
Is more to my mind; but these fellows, I find,
Will not let a leader be knightly.
If Balfour would only fight fair;
And impose that condition on Bartley;
If Joe would not ravage and shriek like a savage;
Did Tommy talk less, and less tartly;
Were Goschen less eager for scalps,
And kept a tight rein upon Hanbury;
Why then 'twere all right; we'd soon get through our fight
And hatred in love's flowing can bury.
But no, they're like Soudanese blacks,
All fury and wild ugly rushes.
They shriek and they shock, and they hack and they hock,
Till chivalry shudders and blushes.
And so the machine-gun, I find,
Is just the one thing will arrest 'em.
They've quite lost their head, but a fair rain of lead
Played on them will try 'em and test 'em!
Whir-r-r-r! George! how it's mowing them down,
Their Advance-guard,—"Amendments" they dub them!](https://image.slidesharecdn.com/2383071-250604232710-fa4271bd/85/Nanomaterials-Science-Technology-And-Applications-R-Vasanthakumari-66-320.jpg)
Nanomaterials Science Technology And Applications R Vasanthakumari
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- 6. Nanomaterials: Science, Technology and Applications Edited by R. Vasanthakumari I.B. Shameem Banu Takuya Tsuzuki Abdul Hadi
- 7. Nanomaterials: Science, Technology and Applications Selected, peer reviewed papers from the International Conference on Nanomaterials: Science, Technology and Applications (ICNM’13), December 5-7, 2013, Chennai, India Edited by R. Vasanthakumari, I.B. Shameem Banu, Takuya Tsuzuki and Abdul Hadi
- 8. Copyright 2014 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of the contents of this publication may be reproduced or transmitted in any form or by any means without the written permission of the publisher. Trans Tech Publications Ltd Kreuzstrasse 10 CH-8635 Durnten-Zurich Switzerland http://www.ttp.net Volume 938 of Advanced Materials Research ISSN print 1022-6680 ISSN cd 1022-6680 ISSN web 1662-8985 Full text available online at http://www.scientific.net Distributed worldwide by and in the Americas by Trans Tech Publications Ltd Trans Tech Publications Inc. Kreuzstrasse 10 PO Box 699, May Street CH-8635 Durnten-Zurich Enfield, NH 03748 Switzerland USA Phone: +1 (603) 632-7377 Fax: +41 (44) 922 10 33 Fax: +1 (603) 632-5611 e-mail: sales@ttp.net e-mail: sales-usa@ttp.net
- 9. Preface In recent years, nanomaterials have became the latest research field of interest due to their size-induced unique properties. Nanotechnology has the potential to change all aspects of our lives in such diverse areas including electronics, energy, biomedicine, environment and security. As such, nanoscience is an interdisciplinary research area and its development encompasses various fields of science and engineering. Its applications in real world and commercial developments are already taking place today. In light of the fast-paced advancements in nanoscience and nanotechnology taking place all over the world, it is of interest to capture state-of-the-art research and development in nanotechnology in India and to facilitate collaboration in multidisciplinary research areas. With this end in view, the Nanocentre at the B. S. Abdur Rahman University organized a three day International Conference on “Nanomaterials: Science, Technology and Applications (ICNM’13)” during Dec 5- 7, 2013 in collaboration with Deakin University, Australia, and Universiti Technologi MARA, Malaysia. The main theme of the conference was to address and deliberate on the latest technical status and recent trends in the research and applications of nanotechnology. This is a unique conference with a specific focus on nanomaterials. This conference has been so designed with the view to provide an opportunity for the scientists, engineers, industrialists, students and other professionals from all over the world to interact and exchange their new ideas and research outcomes for future collaboration. The conference was also aimed at motivating the next generation of researchers to promote their interests in nanoscience, nanotechnology and their applications. Over 350 delegates from all over the world were brought together in Chennai to share their latest research in various nanotechnology fields including materials, chemistry, physics, biology, and polymers. To accommodate the large number of lectures, 3 parallel sessions were conducted with the themes in Nano in chemistry and physics, Nano in bio and polymers and Nano in devices and applications. 26 invited talks including 3 plenary lectures, 3 keynote lectures and 20 invited lectures were presented by world- class experts from various organizations and Universities in India and abroad including Australia, Malaysia, UK, USA and Brazil. In addition, 89 oral and 95 poster presentations were given by the research scholars from all over the world. This Proceedings contains 55 selected papers which have been authored by a combined total of 147 authors. Each contributed paper was rigorously peer-reviewed by two reviewers who were drawn from a large pool of Organizing and Advisory Committee members as well as other experts in the field from India and abroad. ICNM13 would not have been possible without the strong support from numerous organizations and individuals. The efforts and support provided by all the authors, reviewers, sponsors, invited speakers, members of advisory board and organizing team comprising students and faculty volunteers and all others who have contributed to the successful organization of this conference, are gratefully acknowledged. Special thanks are due to Vice Chancellors of B S Abdur Rahman University, UiTM, Malaysia and Deakin University for making ICNM13 a grand success. Dr R.Vasanthakumari B S Abdur Rahman University March 2014
- 10. ADVISORY AND ORGANISING COMMITTEE Dr. R. Vasanthakumari B S Abdur Rahman University – Organising Chair Dr. I. B. Shameem Banu B S Abdur Rahman University – Organising Chair Dr. Jagat R. Kanwar Deakin University, Australia – Chair Dr. Takuya Tsuzuki Australian National University, Australia – Chair Dr. Abdul Hadi Universiti Teknologi MARA, Malaysia – Chair Mr. Abdul Qadir Rahman Buhari A Chairman, B S Abdur Rahman University, India Jane Den Hollender Vice Chancellor, Deakin University, Australia Prof. Ir. Dr. Sahol Hamid Abu Bakar Vice Chancellor, Universiti Teknologi MARA, Malaysia Prof. J A K Tareen (Padma Shri) Vice-Chancellor, B S Abdur Rahman University, India Dr. V M Periasamy Pro-Vice Chancellor, B S Abdur Rahman University, India Dr. V Murugesan Registrar, B S Abdur Rahman University, India Mr. V N A Jalal Director (Admin), B S Abdur Rahman University, India Dr. A. Hannah Rachel Vasanthi Pondicherry University, Pondicherry Dr. Abdel Hadi Kassiba Université du Maine, France Dr. Arunachalam Dharmarajan Curtin University, Australia Dr. Ashok M NIT, Trichy, India Dr. Brett Kirk Curtin University, Australia Dr. David F L Jenkins Plymouth University, UK Dr. Jacob Muthu University of Witwatersrand, South Africa Dr. Jayavel R Anna University, Chennai, India Dr. John V. Kennedy NIC GNS, New Zealand Dr. K S Dhathathreyan ARCI, Taramani, Chennai Dr. Kishorchandra Rewatkar Dr. Ambedkar College, Nagpur Dr. Kulkarni G U JNCASR, Bangalore, India Dr. M S Ramachandra Rao IIT Madras, India Dr. Mani V N C‐MET, Hyderabad, India Dr. Mohan Rao G IISc, Bangalore, India Dr. Mohd NasirTaib Universiti Teknologi, MARA, Malaysia Dr. Murali Rangarajan Amrita Vishwa Vidyapeetham, Coimbatore Dr. Natarajan T.S IIT, Madras, India Dr. Norlida Kamarulzaman Universiti Teknologi, MARA, Malaysia Dr. Pradeep T IIT Madras, Chennai, India Dr. Pramanik IIT, West Bengal, Kharakpur, India Dr. Rasiah Ladchumananandasivam Centre of Technology, URN, Brazil Dr. Rita John University of Madras, India Dr. Seeram Ramakrishna NUS, Singapore Dr. Singh V R IEEE Delhi, New Delhi, India Dr. Sitaram Dash IGCAR Kalpakkam, India Dr. Subrahmanyam A IIT Madras, Chennai, India Dr. Tarasankar Pal IIT Kharagpur, India Dr. V. Rajendran KSRCT, India Dr. Vasu Punj University of Southern California, USA Dr. Vijayamohanan K. Pillai CECRI, Karaikudi, India
- 11. LOCAL ORGANISING COMMITTEE Dr. S. S. M. Abdul Majeed, Polymer Engg Dr. S. K. Rani, Chemistry Dr. D. Easwaramurthy, Chemistry Dr. K. Karthikeyan, Chemistry Dr. M. Basheer Ahamed, Physics Dr. I. Raja Mohamed, Physics Dr. P. M. Usha Rani, English Dr. S. Hemalatha, Life Science Mr. G. V. Vijayaraghavan, Physics Mr. M. Mohamed Sheik Sirajudeen, Physics Dr. J. Thirumalai, Physics Dr. R. Indirajith, Physics Dr. S. Krishnan, Physics Dr. E. Manikandan, Physics Dr. R. Karthikeyan, Life Science Dr. S. Chandran, P.Edu. Dr. Revathy Purushothaman, Chemistry Dr. S. Bhagavathy, Chemistry Dr. S. Mahasampth Gowri, Chemistry Dr. J. Elangovan, Chemistry Dr. A. Shahjahan, Chemistry Dr. J. Herbert Mabel, Chemistry Mr. D. Murali Manohar, Polymer Engg Mrs. J. Shahitha Parveen, Polymer Engg Mr. Basanta Kumar Behera, Polymer Engg Ms. S. Shamshath Begum, Polymer Engg Ms. M. Katheeja Parveen, CA Mr. F. Abubecker, AR/PRO Dr. P. Panneerselvam, Library Mr. M. Meenakshi Sundaram, Est. office Ms. K. P.Sindhu, Polymer Engg Mr. D. Shanmugam, Canteen Manager Dr. T. R. Rangaswamy, Dean (Academics) Dr. I. Mohammed Bilal, Controller of Exam Mr. L. Aravindh Kumaran, CBS Mr. I. Hasan Abdul Kader, Est. office Dr. K. Boopathy, EEE Ms. S. Vijayarani, Polymer Engg Mrs. K. Yogeswari, Arch. Mr. S. Vikram, PNTC Mr. S. Akbar Basha, Civil Mrs. R. Gayathri, PNTC Dr. P. S. Sheik Uduman, Maths Mr. A. Musammil Hareed, PNTC Dr. A.S. Prasanna Venkatesh, Maths Mr. G. Dhanasekaran, Polymer Engg Dr. Md Khurshid Alam Khan, Life Science Mr. R. Krishnan, Physics Dr. Soumen Bera, Life Science Mr. G. Shanmuganathan, Physics Dr. M. K. Sangeetha, Life Science Ms. R. Rizwana, Physics Dr. P. Rathna, English Ms. A. Sathiya Priya, Physics Mrs. A. Catherine Anna Pushpam, English Ms. R. Sasikala, Chemistry Mrs. S. Grace Vinitha, English Mr. R. Mohanraj, Chemistry Mr. R. Sathish Kumar, Mech. Mrs. S. Thilagavathy, Chemistry Dr. Naseer Ahmad, Life Science Mr. D. Somasundaram, Chemistry Mrs. L. Annagowsalya , Mech. Mr. T. R. Ashok Kumar, Physics Mr. Sudarshan, ECE (Student Sec.) Mr. G. Somasundaram, Chemistry
- 12. Organized by B.S.ABDUR RAHMAN UNIVERSITY, INDIA DEAKIN UNIVERSITY, AUSTRALIA UNIVERSITI TEKNOLOGI MARA, MALAYSIA
- 13. Sponsors Department of Science and Technology Ministry of Science and Technology Department of Bio Technology Ministry of Science and Technology S R M UNIVERSITY RELIANCE INDUSTRIES LIMITED CIPET THE HINDU INDIAN OVERSEAS BANK, VANDALUR Branch APOLLO TYRES THERMO FISHER SCIENTIFIC PANALYTICA INDIA SPECTRIS TECHNOLOGIES PVT LTD RANGA TECHNO IMPEX
- 14. Plenary and Keynote Lectures Multifunctional Chimeric Survivin Targeted Nano-bullets against Cancer Stem Cells Dr. Jagat Kanwar, Deakin University, Australia Clusters, nanoparticles and water Dr. T. Pradeep, IIT Madras, Chennai Physics and Applications of Nanostructures and Nanomaterials Dr. M. S. Ramachandra Rao, IIT Madras, Chennai Life Cycle Assessment of Nanomaterials: Towards Green Nanotechnology Dr. Takuya Tsuzuki, Australian National University, Australia Metal oxide nanostructures and metal oxide thin films Dr. Norlida Kamarulzaman, Universiti Teknologi, MARA, Malaysia Invited Lectures Structure and electric-magnetic properties of nanosized hexaferrites synthesized by sol gel auto combustion technique for high frequency applications. Dr. Kishore Chandra Rewatkar, Dr. Ambedkar College, Nagpur Nanocomposite substrates for surface enhanced Raman scattering (SERS) down to single molecular level Dr. Tarasankar Pal, IIT Kharagpur Synthesis and application of TiO2 nanocoating on PLA fibres by pulsed dc magnetron sputtering (PMS) Dr. Rasaiah Ladchumanandasivam, URN, Brazil Polymer nano-composites: an engineering perspective Dr. Jacob Muthu, University of Witwatersrand, South Africa Biocompatible nanocomposites for tissue engineering applications Dr. V. Rajendran, KSRCT, Thiruchengode Electrospun metal-oxide nanofibers and their applications Dr. T. S. Natarajan, IIT Madras, Chennai Study on the microstructure and redox properties of CexZr(1-x)O2 nanocatalysts Dr. Abdul Hadi, Universiti Teknologi, MARA, Malaysia Thin film microbatteries – power sources for next generation devices Dr .G. Mohan Rao, IISc, Bangalore
- 15. Wnt Antagonist, Secreted Frizzled-Related Protein-4 (sFRP4), Increases Chemotherapeutic Response Of Glioma Stem-Like Cells Dr. Arunachalam Dharmarajan, Curtin University, Australia Quantifying the relationship between the biomechanical properties and microstructure of connective tissues Dr.Brett Kirk, Curtin University, Australia Interesting aspects of heavy metal interaction with biopolymer composites for environmental remediation Dr.N. Rajesh, BITS-Pilani, Hyderabad Campus Detecting Silver Nanoparticles in Aqueous Colloids with Surface Plasmon Resonance – Challenging the Limits of Dynamic Light Scattering Dr. David F. Jenkins, Plymouth University, UK Graphene-metal oxide composites with improved properties for photo catalytic and super capacitor applications Dr. R. Jayavel, Anna University, Chennai Functionalized graphene as electrochemical sensing platform Dr. Murali Rangarajan, Amrita Vishwa Vidhyapeedam, Coimbatore Role of advanced nano pure electronic materials and devices in strategic aerospace/ defence applications – a bird’s eye view and select results on the preparation of nano pure gallium for GaAs technology - an indigenous effort Dr. V. N. Mani, C-MET, Hyderabad Influence of Transition metals on the Optical and Magnetic properties of Nano ZnO Dr. Rita John, University of Madras, Chennai Nanomedicine of Ancient Times - A Scientific Study of a Herbometallic Siddha drug Tamira Parpam Dr. A. Hannah Rachel Vasanthi, Pondicherry University, Pondicherry Nanostructured Coatings for Surface Engineering Applications Dr. Sitaram Dash, IGCAR, Kalpakkam Recent developments in Electrocatalysts for Low Temperature Fuel Cells at ARCI Dr. K S Dhathathreyan, ARCI, Taramani, Chennai
- 16. Table of Contents Preface, Committees and Organizers, Sponsors, Plenary and Keynote Lectures and Invited Lectures I. Nano Materials: Synthesis and Characterisation Synthesis and Characterization of Zn Nanoparticles by Using Hetero-Bicyclic Compound V. Pushpanathan and D.S. Kumar 3 Hexamine Assisted Hydrothermal Synthesis of Eu3+ Activated Na0.5La0.5MoO4 Microstructures: Synthesis, Structure and Morphological Investigations R. Krishnan, J. Thirumalai, G. Shanmuganathan, I.B. Shameem Banu and R. Chandramohan 9 Effect of Surfactants on Structural and Dielectric Properties of Cobalt Ferrite H. Khatri, G. Packiaraj and R.B. Jotania 14 Modified Sol-Gel Production of Nano SDC20 Materials S. Ramesh, K.C. James Raju and C.V. Reddy 19 Effect of Heat Treatment on Structural, Magnetic and Electric Properties of Z-Type Barium Cobalt Hexaferrite Powder N. Solanki, G. Packiaraj and R.B. Jotania 24 Kinetics of Silver Nanoparticle Growth Using DMF as Reductant – Effect of Surfactants P. Sarkar, C. Parameswaran, C. Harish, M.B. Chandra and A.N. Grace 30 Microstructure and Adhesion Properties of a-CN and Ti/a-CN Nanocomposite Thin Films Prepared by Hybrid Ion Beam Deposition Technique P. Vijai Bharathy, Q. Yang and D. Nataraj 36 In Situ Synthesis of Copper Phthalocyanine Modified Multiwalled Carbon Tube and its Electrocatalytic Application towards the Oxidation of Nitrite K.N. Porchelvi, S. Meenakshi and K. Pandian 40 Study on the Structure and Morphology of CexZr(1-x)O2 Mixed Oxides M.N. Abu Shah, S.H. Md Nor, K.N. Ismail and A. Hadi 46 Morphological Studies of Electrodeposited Cobalt Based Coatings: Effect of Alloying Elements N.A. Resali, K. Mei Hyie, W.N.R. Abdullah and N.H. Saad 52 Plasma Enhanced Chemical Vapor Deposition Time Effect on Multi-Wall Carbon Nanotube Growth Using C2H2 and H2 as Precursors Y. Noriah, N.H. Saad, M. Nabipoor, S. Sulaiman and D.B.C. Sheng 58 Structural, Electrical and FT-IR Studies of Nano Zn1-xCaxO by Solid State Reaction Method T. Das, B.K. Das, K. Parashar, S.K.S. Parashar and R.A. Nagamalleswara 63 Crystal Structural Studies of ZnO Nanorods and their Band Gaps M.F. Kasim, N. Kamarulzaman and S.A. Kamil 71 Synthesis of Silicon Nanostructures Using DC-Arc Thermal Plasma: Effect of Ambient Hydrogen on Morphology C.M. Tank, V.B. Varma, S.V. Bhoraskar and V.L. Mathe 76 II. Electrical, Magnetic, Optical Properties of Nanomaterials Effect of Cobalt Concentration on Bi0.95Ba0.05Fe1-xCoxO3 P.R. Vanga, S. Leelashree and M. Ashok 85 Synthesis, Magnetic and Surface Properties of Reduced Graphene Oxide Supported Nickel Oxide Hybrid Nanomaterials M.J. Ganpath, R. Rajendiran and V. Rengarajan 91 Study of Electronic and Magnetic Properties of Nitrogen Doped Graphene Oxide E. Jayabal, R. Rajendiran and V. Rengarajan 97 Structural and Optical Properties of Nebulized Nickel Oxide Thin Films V. Gowthami, M. Meenakshi, N. Anandhan and C. Sanjeeviraja 103
- 17. b Nanomaterials: Science, Technology and Applications Electrical Conductivity Properties of Nd2O3 Doped LiCl-PbO-ZnO Glass Ceramics M. Sathish and B. Eraiah 108 Synthesis of Cu2O Nanospheres and Cubes: Their Structural, Optical and Magnetic Properties G. Prabhakaran and R. Murugan 114 Near-Field Scanning Optical Microscopy: Single Channel Imaging of Selected Gold Nanoparticles through Two Photon Induced Photoluminescence M.K. Hossain, M. Kitajima, K. Imura and H. Okamoto 118 Investigation of Optical Properties of ZnO/MnO2, ZnO/TiO2 and ZnO/MnO2/TiO2 Nanocomposites G. Shanmuganathan and I.B. Shameem Banu 123 Structural and Magnetic Properties of Ultrafine Magnesium Ferrite Nanoparticles P.M. Md Gazzali, V. Kanimozhi, P. Priyadharsini and G. Chandrasekaran 128 Structural, Morphological, Optical, and Magnetic Properties of Fe-Doped CuO Nanostructures N.M. Basith, J.J. Vijaya and L.J. Kennedy 134 Synthesis, Structural and Dielectric Properties of Pure and Ni Substituted Bismuth Ferrite S. Blessi, S. Vijayalakshmi and S. Pauline 140 Synthesis and Characterization of Novel ZnO Nanophosphors M.S. Kurrey and B.D. Diwan 145 III. Polymers and Nanocomposites Synthesis of Polythiophene and its Carbonaceous Nanofibers as Electrode Materials for Asymmetric Supercapacitors K. Balakrishnan, M. Kumar and A. Subramania 151 Studies on Dual Phase Conducting Polyaniline Magnetic Micro and Nanocomposites V. Srinivas, V. Raju, L. Joseph and J. Syed 158 Studies on the Depolymerization of Poly(ethylene terephthalate) Using 1, 1, 2, 2- Tetramethyl-1-Benzyl-2-n-Octyl Ethylene-1, 2-Diammonium Bromide Chloride as Phase Transfer Catalyst V.L. Narayanan and M.J. Umapathy 164 Nanomaterials in PU Foam for Enhanced Sound Absorption at Low Frequency Region R. Gayathri and R. Vasanthakumari 170 Cadmium Selenide Quantum Dots - MWCNTs Nanocomposite Modified Electrode for the Determination of Epinephrine A. Kalaivani and S.S. Narayanan 176 Single Step Synthesis of Gold Nanoparticles Decorated Graphene Oxide Using Aniline as Reducing Agent and Study its Application on Elecrocatalytic Detection of Tryptophan P. Divya, A. Sudarvizhi and K. Pandian 182 Synthesis of Chitosan Protected Nickel Hexacyanoferrate Modified Titanium Oxide Nanotube and Study its Application on Simultaneous Electrochemical Detection of Paracetamol and Caffeine S. Devi and K. Pandian 192 Effect of Stirring on Hydrophobicity of PVDF/CNT Nanocomposite Coatings G. Prasad and A. Anand Prabu 199 Impedance Spectroscopic Studies on Natural Rubber-TiO2 Nanocomposite T. Praveen and P. Predeep 204 Nanocomposites Based on High-Tc Superconducting Ceramic 2212 BSCCO and their Properties T.K. Jayasree and P. Predeep 210 Synthesis and Characterization of Bi2S3 Nanorods Decorated on Carbon Sphere and Study its Electrochemical Application P. Devendran, T. Alagesan and K. Pandian 215 IV. Bio Nanomaterials and their Applications
- 18. Advanced Materials Research Vol. 938 c Temperature Dependent Electrical Properties of Green Synthesized Silver Nanoparticles- Polyaniline Composite M. Dorairajan, V. Srinivas, V. Raju and G. Raghavan 230 Green Synthesis of Silver Nanoparticles by Haloarchaeon Halococcus salifodinae BK6 P. Srivastava, J. Braganca, S.R. Ramanan and M. Kowshik 236 Physicochemical Studies on Nano Silver Particles Prepared by Green and Chemical Methods V.D. Praveena and K.V. Kumar 242 V. Nanomaterials: Energy & Environment Overlithiation of LiNi0.8Co0.2O2 for Increased Performance in Li-Ion Batteries H. Rusdi, N. Kamarulzaman, R. Rusdi, K. Elong and A. Abd Rahman 253 Photodegradation Studies on Orange G and Acid Blue 113: New Doped Rare Earth Nanometal Oxides as Visible Light Active Photo Catalyst G.A. Suganya Josephine and A. Sivasamy 257 Hydrogen Peroxide Sensor Based on Carbon Nanotubes - Poly(celestine blue) Nanohybrid Modified Electrode N.S. Sangeetha and S. Sriman Narayanan 263 Development of Environmentally Acceptable Nano-Hybrid Coatings for Bio-Fouling Protection P. Saravanan, D. Duraibabu and S.A. Kumar 269 Synthesis of PVDF-co-HFP-ZrO2 Based Composite Polymer Electrolyte for Battery Applications M. Johnsi and S.A. Suthanthiraraj 275 Silver Nanoparticles on Zinc Oxide: An Approach to Plasmonic PV Solar Cell M.K. Hossain, Q.A. Drmosh, F. Al Harabi and N. Tabet 280 Experimental Investigation of Aqueous Cerium Oxide Nanofluid Blend in Diesel Engine S.P. Venkatesan, P.N. Kadiresh and K.S. Kumar 286 Nano Gold Doped Nano TiO2 – An Efficient Solar Photocatalyst for the Degradation of Persistent Organic Pollutants J. Thomas and K.R. Chitra 292 VI. Nanomaterials: Theoretical and Computational Studies System Identification in Modified Diabetic Model for Nanochip Controller N.F. Binti Mohd Yusof, A. Md. Som, A.S. Ibrehem and S. Abdulbari Ali 299 Quantum Noise Suppression in Two Dimensional Photonic Crystal Fibers G.M. Latha, M. Sripriya and N. Ramesh 305 Photo-Luminescence Properties of Novel ZnO Nano-Phosphors M.S. Kurrey and B.D. Diwan 311 Silicon Nanowire Embedded Spiral Photonic Crystal Fiber for Soliton-Effect Pulse Compression E. Gunasundari, K. Senthilnathan, S. Sivabalan, K. Nakkeeran and P.R. Babu 316 Influence of Size on Effective Band Gap of Silicon Nano-Wire B.D. Diwan and V.K. Dubey 322
- 19. I. Nano Materials: Synthesis and Characterisation
- 20. Synthesis and Characterization of Zn Nanoparticles by using Hetero-bicyclic Compound V. Pushpanathana and D. Suresh Kumarb * Supramolecular Research Laboratory, Department of Chemistry, Loyola College, Chennai-600034, India a push.josephite@gmail.com, b drdsklc@gmail.com Keywords: Bicyclic compound, Zn nanoparticle, Benzil, Reducing and Stabilizing agent Abstract: The 1:1 condensation reaction between benzil and tris(hydroxymethyl)aminomethane in methanol yields a hetero bicyclic compound 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza- bicyclo[3.2.1]octan-2-ol. It was characterized by FT-IR, NMR (1 H and 13 C) spectroscopy and ESI mass spectrometry. The structure was conclusively determined by X-ray diffractrometric analysis. The structure shows a hetero bicyclic ring system. It consists of six membered morpholine and five membered oxazolidine rings with free hydroxyl groups. This bicyclic compound was used as a reducing and stabilizing agent to prepare zinc nanoparticles. The morphology and structure were characterized by field emission scanning electron microscope (FE-SEM), powder X-ray diffraction (XRD), and energy dispersive spectrum analysis (EDS). Introduction Nanoparticles have attracted much attention due to their unique optical, electronic, magnetic, mechanical and chemical properties compared with those of the same bulk material. These properties can be tuned by controlling their size and shape [1]. In the synthesis of nanoparticles, the main problem is their stabilization and monitoring of their size and size distribution. Many strategies have been employed for synthesizing metal nanoparticles including hydrothermal synthesis [2], spray pyrolysis [3], sonochemical synthesis, microwave assisted synthesis [4], chemical reduction in the presence of a stabilizing agent such as polymers or surfactants, [5-7] electrochemical processes [8], sol-gel processes [9], and so forth. Zn nanoparticles are the most important metal nanoparticles for such wide ranging applications as piezoelectric transducers, gas sensors, transparent conductive films, light-emitting devices, photo detectors and solar cell windows [10, 11]. Usually when metal nanoparticles are synthesized by chemical methods, the metal ions reduced by the reducing agents [12] and protecting agents or phase transfer agents are also added to stabilize the nanoparticles. Several types of toxic reducing agents containing boron commonly have been employed to produce metal nanoparticles from inorganic salts; the resulting metal nanoparticles are contaminated with borides. Hence investigation on the synthesis of boride free metal nanoparticles has more significance especially for use in biological and medical purposes. Here we report the novel synthesis of zinc nanoparticles using hetero bicyclic compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol as a reducing as well as stabilizing agents and their characterization by spectral techniques. Experimental Materials. Benzil, tris(hydroxymethyl)aminomethane and zinc(II) nitrate hexahydrate were purchased from commercial sources and used as such. Solvents were of analytical grade and were purified prior to use. Analytical and physical measurements. Micro analytical (C, H, N) data were obtained with a FLASH EA 1112 Series CHNS Analyzer. The IR spectra (with KBr pellets) were recorded in the range of 400-4000 cm-1 on a JASCO FT/ IR-5300 FT-IR spectrometer. 1 H and 13 C NMR spectra were recorded on a Bruker AVANCE III 400 MHz (AV400) multinuclear NMR spectrometer at 400 Advanced Materials Research Vol. 938 (2014) pp 3-8 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.3
- 21. MHz and 100 MHz, respectively. ESI mass spectra were obtained on a LCMS-2010A Shimadzu spectrometer. The crystal data were collected on a Bruker axs kappa APEXII CCD Diffractometer. Powder X-ray diffraction patterns were recorded on a Bruker D8-Advance diffractometer using graphite monochromated CuKα1 (1.5406Å) and Kα2 (1.54439Å) radiations. The SEM image and EDS spectrum of the zinc nanoparticles were examined using HITACHI S-4300SE/NFESEM and a beam voltage of 20 kV. Synthesis of hetero bicyclic compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8- aza-bicyclo[3.2.1]octan-2-ol (L1). To a hot solution of benzil (2.10 g, 10 mmol) in methanol, tris(hydroxymethyl)aminomethane (1.21 g, 10 mmol) in methanol was added in drops and refluxed for 4 h. The resultant clear solution was kept for a day to obtain colourless crystals. The crystals were washed in cold methanol and dried in desiccator. Yield: 80%. Mp: 190◦ C (dec.). Elemental analysis, Found (%): C, 68.95; H, 6.19; N, 4.33. Calc. for C18H19NO4 (%): C, 68.99; H, 6.11; N, 4.47. Mass spectrum (ESI): m/z 314 (MH+ ), 336 (M+Na+ ). 1 H-NMR (CD3OD) 3.47–3.80 (m, 4H), 4.03 (dd, 1H), 4.22 (d, 1H), 4.44 (d, 1H), 4.99 (s, 1H), 7.03–7.54 (m, 10H).13 C-NMR (CD3OD) 61.6, 65.48, 68.15, 70.07, 98.62, 98.62, 124.97, 126.86, 127.22, 128.09, 128.92, 130.96. Scheme 1. Preparation of hetero-bicyclic compound (L1). Synthesis of zinc nanoparticles. To a hot solution of reducing agent, 5-(hydroxymethyl)- 1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol (0.313 g, 1 mmol.) in methanol (30ml), a solution of zinc(II) nitrate hexahydrate (1 mmol) in deionized water (10 ml) was added in drops for 30 min. The resultant solution was stirred and refluxed for 3 h under nitrogen atmosphere. On keeping the solution overnight, the zinc nanoparticles were formed. These particles were separated out by centrifugation, washed repeatedly with acetone to remove reducing agent and then dried at room temperature. 4 Nanomaterials: Science, Technology and Applications
- 22. Results and Discussion In 2005, Giovenzana et al. reported that the reaction of benzil and tris(hydroxymethyl)aminomethane in equimolar proportion yields colorless hetero-bicyclic compound, 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo[3.2.1]octan-2-ol (L1) instead of L2 as shown in Scheme 1. The structure and stereochemistry of the crystalline product (L1) was Fig. 1. (a) An ORTEP diagram and (b) Packing arrangement of crystal (L1) conclusively determined by them using single crystal X-ray crystallography [13]. Our attempt to sysnthesis L3 by stirring a dilute methanolic solution of benzil and tris(hydroxymethyl)aminomethane, in 1:2 ratio and later refluxing, yielded the same crystalline bicyclic compound (L1) instead of expected compound (L3). The obtained single crystal was verified by X-ray crystallography. An ORTEP diagram of the crystal is shown in Fig. 1(a). The crystal data are shown in Table 1. Table 1. Crystallographic data for L1 Empirical formula Formula weight Temperature Wavelength Crystal system Unit cell dimensions a (Å) b (Å) c (Å) α β γ Volume Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection C18H19NO4 313.34 293 K 0.71073 Å Monoclinic, Cc 15.5870 (9) 12.6447 (7) 7.9620 (4) 90.000(3) ° 93.928 (2)° 90.000(3) ° 1565.57 (15) Å3 4 1.329 Mg m−3 0.09 mm−1 664 0.3 × 0.3 × 0.2 mm 2.1–27.5° The crystal structure of the hetero-bicyclic compound consists of six membered morpholine and five membered oxazolidine rings fused together. The six membered ring has chair conformation and the presence of two free hydroxyl groups increases the water solubility of the compound. The two aromatic rings at C5 and C7 are trans to each other with a torsional angle of 53.47°. The crystal packing consists of four bicyclic molecules. They are linked by N—H···O, O—H···O and O— H···N weak interactions, generating a three dimensional-network as shown in Fig. 1(b). No intramolecular hydrogen bonding is observed. The FT-IR spectrum of the compound shows a broad band at 3400 cm-1 due to the presence of alcoholic group. The absorption band at 2903 cm-1 is due to the N-H stretching vibration. The 1 H NMR spectrum of the compound shows multiplets at 3.47-3.86 ppm corresponding to methylenic protons. Aromatic protons resonate in the range 7.05-7.54 ppm. The alcoholic and secondary amine protons are observed at 4.22 and 4.44 ppm, respectively. Advanced Materials Research Vol. 938 5
- 23. Fig. 2. (a) 1 H NMR and (b) 13 C NMR spectrum of hetero bicyclic compound (L1) The 13 C NMR spectrum shows signals at 61.6-70.7 ppm corresponding to aliphatic carbons. The signals in the range of 98.62-130.96 ppm are due to the presence of aromatic carbons. The 1 H and 13 C NMR spectrum are presented in Figs. 2(a) and (b), respectively. The mass spectrum (Fig. 3) shows the molecular ion peak at m/z 314 (MH+ ) which is in confirmation with the theoretical mass of the compound, 313. Fig.3. ESI mass spectrum of hetero bicyclic compound (L1) For preparing metal nanoparticles using chemical reduction method, it is very important to decide appropriate stabilizer. In this work, for synthesizing zinc nanoparticles the hetero-bicyclic compound (L1) is employed as a reducing agent. The method is shown in Scheme 2. It is also observed that L1 acts as a stabilizing agent to protect the nanoparticles from growth and agglomeration. Fig. 4 shows the powder XRD pattern of the as-prepared zinc nanoparticles. Scheme 2. Preparation of Zn nanoparticles. Fig. 4. PXRD pattern of Zn nanoparticles All Braggs’ reflections due to metallic zinc are observed at 36.325, 37.964, 43.2463, 54.355, 70.018 and 77.03 corresponding to the zinc nanoparticles and a very few reflections due to ZnO nanoparticles are observed at 31.772, 34.504, 47.708, 55.995, 67.286. The FE-SEM image reveals that the morphology of the zinc nanoparticles is spherical with dimensions of 20 to 90 nm and the particles surrounded by ZnO have crystalline spots, which are grown coherently with the Zn N2 6 Nanomaterials: Science, Technology and Applications
- 24. nanoparticles. The formation of ZnO nanoparticles could be attributed to the trace amount of dissolved oxygen present in the solvent as impurity [14]. The EDS shows the chemical purity and stoichiometry of the nanoparticles. FE-SEM image and EDS spectrum of the Zn nanoparticles are shown in Figs. 5(a) and (b), respectively. Fig. 5. (a) FE-SEM image of Zn nanoparticles and (b) EDS spectrum Conclusion In this study, the bicyclic compound (L1) acts in a unique way both as reducing and stabilizing agent for the synthesis of zinc nanoparticles. Despite several synthetic methods being available, this method serves as a more simple and significant one for the synthesis of zinc nanoparticles. The nanoparticles obtained are relatively pure and stable for several weeks. Acknowledgements The author (V. Pushpanathan) is thankful to UGC-NRC, School of Chemistry, University of Hyderabad for the instrumentation facility. The authors are also thankful to Head, SAIF, IIT- Madras for the XRD analysis. References [1] I.O. Sosa, C. Noguez, R.G. Barrera, Optical properties of metal nanoparticles with arbitrary shapes, J. Phys. Chem. B 107(26), (2003) 6269–6275. [2] B. Liu, H.C. Zeng, Hydrothermal synthesis of ZnO nanorods in the diameter regime of 50 nm, J. Am. Chem. Soc. 125 (2003) 4430–4431. [3] K. Okuyama, I.W. Lenggoro, Preparation of nanoparticles via spray route, Chem. Eng. Sci. 58 (2003) 537–547. [4] X.L. Hu, Y.J. Zhu, S.W. Wang, Sonochemical and microwave-assisted synthesis of linked single-crystalline ZnO rods, Mater. Chem. Phys. 88 (2004) 421–426. [5] A. Henglein, M. Giersig, Formation of colloidal silver nanoparticles: Capping action of citrate, J. Phys. Chem. B 103 (1999) 9533-9539. [6] Y. Bingsheng, M. Houyi, Electrochemical synthesis of silver nanoparticles under protection of poly(n-vinylpyrrolidone), J. Phys. Chem. B 107 (2003) 8898-8904. [7] X. Jiang, Y. Xie, J. Lu, L. Zhu, W. He, Y. Qian, Preparation, characterization, and catalytic effect of CS2-stabilized silver nanoparticles in aqueous solution, Langmuir 17 (2001) 3795- 3799. Advanced Materials Research Vol. 938 7
- 25. [8] L. Rodriguez-Sanchez, M.C. Blanco, M.A. Lopez-Quintela, Electrochemical synthesis of silver nanoparticles, J. Phys. Chem. B 104 (2000) 9683-9688. [9] P.W. Wu, B. Dunn, V. Doan, B.J. Schwartz, E. Yablonovitch, M. Yamane, Controlling the spontaneous precipitation of silver nanoparticles in sol-gel materials, J. Sol.-Gel Sci. Technol. 19 (2000) 249-252. [10]S. Liang, H. Sheng, Y. Liu, Z. Hio, Y. Lu, H.J. Shen, ZnO Schottky ultraviolet photodetectors, J. Cryst. Growth 225 (2001) 110–113. [11]Y.H. Ni, X.W. Wei, J.M. Hong, Y. Ye, Hydrothermal preparation and optical properties of ZnO nanorods, Mater. Sci. Eng. B 121 (2005) 42–47. [12] S.R. Ghanta, M.H. Rao, K. Muralidharan, Single-pot synthesis of zinc nanoparticles, borane (BH3) and closo-dodecaborate (B12H12)2− using LiBH4 under mild conditions, Dalton Trans., 42 (2013) 8420–8425. [13]G.B. Giovenzana, G. Palmisano, E.D. Grosso, L. Giovannelli, A. Penoni, T. Pilati, Polycyclic compounds from aminopolyols and α-dicarbonyls: structure and application in the synthesis of exoditopic ligands, Org. Biomol. Chem. 3 (2005) 1489–1494. [14] S.C Singh, R. Gopal, Zinc nanoparticles in solution by laser ablation technique, Bull. Mater. Sci., 30 (2007) 291–293. 8 Nanomaterials: Science, Technology and Applications
- 26. Hexamine Assisted Hydrothermal Synthesis of Eu3+ Activated Na0.5La0.5MoO4 Microstructures: Synthesis, Structure and Morphological Investigations Rajagopalan Krishnan1, a , Jagannathan Thirumalai1, b , Govindan Shanmuganathan1, c , Itreesh Basha Shameem Banu1, d , Rathinam Chandramohan2, e 1 Department of Physics, B. S. Abdur Rahman University, Vandalur, Chennai, Tamilnadu, India. 2 Department of Physics, Sree Sevugan Annamalai College, Devakottai, Tamilnadu, India. a krishnanrphy@gmail.com, b thirumalaijg@gmail.com (corresponding author), c shangovinth@gmail.com, d shameembanu@bsauniv.ac.in, e rathinam.chandramohan@gmail.com, Keywords: Hydrothermal route, hexamine, self-assembly, photoluminescence Abstract Highly uniform and self-assembled spheroid-like microstructures of Na0.5La0.5MoO4:Eu3+ were successfully synthesized by hexamine assisted hydrothermal route at 180 °C for 24 hours with neutral pH (7~8). Scanning electron microscope, X-ray diffraction pattern and energy dispersive X- ray analysis were used to characterize the morphology, crystal structure, size, and elements of the particles. It is found that, the particle size was well-controlled by increasing the molar concentration of the chelating agent hexamine. While, irradiating at 395 nm UV light, the emission spectra of micro-spheres shows remarkable characteristic dominance of red emission which is attributed to the transition 5 D0→7 F2. Furthermore, the synthesized homogeneous and well-crystallized Na0.5La0.5MoO4:Eu3+ microstructures will serve as an excellent phosphor candidate to produce high- quality luminescence for display devices in future. 1. Introduction Self-aggregated 3D micro/nanostructures with well controllable size and morphology have attracted and become hot research topic of investigation. In the recent years, momentous advancement has been made in the self-organization of hierarchical architectures for the fabrication of micro/nanostructured materials and devices. Especially, monodispersed and self-organized three dimensional superstructures and their size dependent properties have initiated worldwide intense research due to their potential applications in fluorescent probes for biological staining, high- performance luminescence device, highly efficient catalysts, opto-electronic device, and biomedical applications based on their novel electronic and optical properties [1,2]. For example, Sheaf-like orthorhombic Gd2(MoO4)3:Eu3+ nanostructures [3], rugby-like Na0.5La0.5MoO4:Eu3+ micro structures [4], ordered nanorods composed of nanoparticles of NaLa(MoO4)2:Eu3+ [5], self- assembled 3D flower-like NaY(MoO4)2:Eu3+ structures [6], etc., Therefore, the development of a reliable and convenient synthetic route that can control the shape of nanostructures under ambient conditions must be important for lighting and display applications. Among the conventional solution based technique, hydrothermal route has lot of advantages which include simplicity, convenience and its being an innovative route to synthesis various micro/nanostructures at a relatively low temperature. In recent years, lanthanide-doped luminescent micro/nano-sized particles have received much attention for their wide applications on high-resolution displays, integrated optical systems, and substitute for organic dyes, solid-state lasers, and especially biological labels. In particular, Advanced Materials Research Vol. 938 (2014) pp 9-13 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.9
- 27. scheelite-type crystal structures of molybdates and tungstates doped with different rare earth ions has been extensively studied in the field of opto-electronics and laser technology due to 4f electronic configurations of rare earth ions [5]. The compound Na0.5La0.5MoO4 possesses a scheelite-type crystal structure in which Mo6+ are populated in the centers of tetrahedral symmetry and Na+ and La3+ are populated in the dodecahedral sites in the tetrahedral symmetry [7]. In this paper, we have investigated controlled synthesis of three dimensional hierarchical micro- architectures of Na0.5La0.5MoO4:Eu3+ by hexamine-assisted facile hydrothermal route. To investigate the effect of the chelating reagent on the fabrication of 3D micro/nanostructures, different molar concentration of hexamine was used in the reaction process. 2. Experimental procedure All reagents were analytical grade and were used without further purification in the experiment. In a typical synthesis, first La2O3 and Eu2O3 dissolved in a stoichiometric amount of diluted hydrochloric acid, and transparent solutions were prepared using appropriate molar concentrations and stirred vigorously for 15 min. The stoichiometric amount of Na2MoO4 was dissolved in 30 mL of double-distilled water under vigorous stirring. Then, the two solutions were carefully mixed; a white colloidal precipitate appeared immediately. This is followed by 0.5-1.0 mM of hexamethylenetetramine dissolved in 15 mL of double-distilled water and carefully added to the white colloidal solution. The obtained pH value of the mixed solution was adjusted to 7-8 by adding NaOH solution. After stirring for about 30 h, the resultant solution was transferred into a closed teflon-lined vessel sealed, and heated at the temperature of 180–200°C for approximately 24 h. When the vessel had cooled to room temperature, the solid product was collected by filtration, and washed with deionized water to remove the residue by centrifugation at 1500 rpm for 30 min to produce a white precipitate, and then dried at 70°C. 3. Result and discussion 3.1 Structural and morphological investigation Fig. 1 shows the X-ray diffraction pattern of Na0.5La0.5MoO4: Eu3+ samples prepared with different molar concentrations of hexamine, 0.5 mM (A1), 1.0 mM (A2) using the hydrothermal route at 180 °C for 24 hrs. It indicates all the peaks in XRD pattern are good in agreement with the standard JCPDS card No. 79-2243 of Na0.5La0.5MoO4. A good crystalline products are successfully synthesized and their strongest intensity peaks are at 2θ =28.05 and 45.90 degrees corresponds to 112 and 204 planes, respectively. XRD pattern reveals that they belong to tetragonal phase with scheelite structure with space group I41/a. No other additional peaks of impurity phases were detected. Fig. 1 X-ray diffraction (XRD) patterns of Na0.5La0.5MoO4:Eu3+ of spheroid-like micro- structures prepared by modulating the amount of hexamine at (A1) 0.5 (A2) 1.0, with a fixed [La3+ /Eu3+ ] concentration. 10 Nanomaterials: Science, Technology and Applications
- 28. Fig. 2 Low –magnification SEM images of Na0.5La0.5MoO4:Eu3+ 3D structures prepared by hydrothermal route at 180°C for 24 h with different molar ratio of hexamine: 0.1 (a), 0.5 (b), 1.0 (c), respectively. (d) Energy dispersive X-ray spectrum (EDX) of Na0.5La0.5MoO4:Eu3+ prepared with 1.0 mM of hexamine. The morphology of Na0.5La0.5MoO4:Eu3+ hierarchical 3D structures in the presence of hexamethylenetetramine (hexamine) as surface capping agent were studied. Electron microscopy (SEM) images of the sample prepared using the typical procedure is shown in Fig. 2. The effect of surfactant (0.1 mM, 0.5mM, 1.0mM) on the morphology of Na0.5La0.5MoO4:Eu3+ was investigated by modulating the molar ratio of hexamine with a fixed [La3+ /Eu3+ ] and MoO4 2- . It was found that the molar ratio of hexamine introduced to the reaction system had a crucial effect on the morphology and size distribution of the final products. It is observed that the molar ratio of hexamine was lower than 0.5 mM; 2D nanosheets are joined to form irregular sphere-like morphology and it became the predominated product (Fig. 2a). The SEM image (Fig. 2b) of Na0.5La0.5MoO4:Eu3+ obtained with 0.5 mM of hexamine shows that nanosheets were further stacked together to form spherical morphology with an average of 2.0 µm in diameter. The molar ratio of hexamine was increased to 1.0 mM, the corresponding SEM images (Fig. 2c) shows nearly uniform spheroids with an average diameter of 3.40 µm. From the above morphological investigation the addition of hexamine into very small amount, can dramatically affect the final morphology of the products. The corresponding SEM images (Fig. 2 (a-c)) clearly indicate the increase of particle size of Na0.5La0.5MoO4:Eu3+ . Further, the EDX (Fig. 2d) spectrum confirms the presence of elements La, Eu, Na, Mo, and O in the product. 3.2 Photoluminescence properties A moderately resolved PL emission spectra (Fig. 3), shows the Stark splitting pattern of 5 D0→7 FJ (where J = 1, 2, 3, 4) intra-configurational f–f electronic transitions of Eu3+ activated Na0.5La0.5MoO4 microstructures. The emission (λex =395 nm) spectra of the Na0.5La0.5MoO4:Eu3+ prepared with 1.0 mM concentration were recorded within the range from 575 to 700 nm at room temperature. Upon excitation with 395 nm UV irradiation, the emission spectra were dominated by the hypersensitive red emission [3], showing a transition 5 D0→7 F2 (due to electric dipole transition) stronger than 5 D0→7 F1 (magnetic dipole). The presence of electric dipole transition confirmed that Eu3+ ions were located at sites without inversion symmetry (C3v symmetry). The other transitions 5 D0→7 F1, 5 D0→7 F3 and 5 D0→7 F4 were relatively very weak. The presence of strong luminescent Advanced Materials Research Vol. 938 11
- 29. intensity indicated the perfection of the microstructures of Na0.5La0.5MoO4:Eu3+ and good crystallization. In the present case, Na0.5La0.5MoO4:Eu3+ belongs to scheelite tetragonal structure and the transition of Eu3+ shows major lines with a bright red emission. These results may be important in the fabrication of high-resolution optical detectors and high-definition luminescent displays. Fig. 3 Photoluminescence emission spectra (λex = 395 nm) of Na0.5La0.5MoO4: Eu3+ samples prepared with 1.0 mM hexamine concentration. 4. Conclusion The red phosphor Na0.5La0.5MoO4: Eu3+ has been successfully synthesized via a facile and mild hydrothermal route employing hexamine as a surfactant. The phase of the crystal structure was identified by X-ray diffraction pattern. The SEM image shows that when the molar concentration of hexamine increases from 0.5mM to 1.0 mM, the size of the particles increases. The photoluminescence properties of Na0.5La0.5MoO4:Eu3+ were thoroughly investigated. The material shows bright red emission from the hypersensitive 5 D0→7 F2 transition (615 nm) at 395 nm UV excitation. In this case, optimal molar concentration of hexamine for Na0.5La0.5MoO4:Eu3+ matrix in hydrothermal route is 1.0 mM. We hope this material has potential application on the display device and is an efficient red phosphor candidate in the high quality luminescence display device for the future. References [1] X. Wang, J. Zhuang, J. Chen, K. Zhou and Y. D. Li, Thermally stable silicate nanotubes, Angew. Chem. Int. Ed., 43 (2004) 2017-2020. [2] J.T. Hu, M. Ouyang, P.D. Yang, C.M. Lieber, Controlled growth and electrical properties of heterojunctions of carbon nanotubes and silicon nanowires, Nature, 399 (1999) 48-51. [3] J. Thirumalai, R. Krishnan, I. B. Shameem Banu, R. Chandramohan, Controlled synthesis, formation mechanism and luminescence properties of novel 3-dimensional Gd2(MoO4)3:Eu3+ nanostructures, J. Mater Sci. Mater Electron., 24 (2013) 253-259. [4] R. Krishnan, J. Thirumalai, I.B.S. Banu and A. John Peter, Rugby like Na0.5La0.5MoO4:Eu3+ 3D architectures: Synthesis characterization and its luminescence behavior, J. Nanostructure in Chem., 3 (2013) 14-19. 12 Nanomaterials: Science, Technology and Applications
- 30. [5] M. Yang, H. You, Y. Jia, H. Qiao, N. Guo, Y. Song, Synthesis and luminescent properties of NaLa(MoO4)2:Eu3+ shuttle-like nanorods composed of nanoparticles. Cryst., Eng.13 (2011) 4046–4052. [6] Y. Huang, L. Zhou, L. Yang, Z. Tang, Self-assembled 3D flower-like NaY(MoO4)2:Eu3+ microarchitectures: hydrothermal synthesis, formation mechanism and luminescence properties. Opt. Mater.33 (2011) 777–782. [7] G.M. Kuz’micheva, V.B. Rybakov, V.L. Panyutin, E.V. Zharikov, K.A. Subbotin, Symmetry of (Na0.5R0.5)MO4Crystals (R = Gd, La; M = W, Mo), Rus. J. Inorg. Chem. 55 (2010)1448-1453. Advanced Materials Research Vol. 938 13
- 31. Effect of Surfactants on Structural and Dielectric Properties of Cobalt Ferrite Hemal Khatri1, a , Packiaraj G.2, b , and R. B. Jotania3, c 1 ,2,3 Department of Physics, University School of sciences, Gujarat University, Ahmedabad – 380009, Gujarat, INDIA. a hhk008@gmail.com, b packiaraj33@gmail.com, c rbjotania@gmail.com Keywords: Spinel ferrite, Cobalt ferrites, Co-precipitation Method, Surfactants, XRD Abstract. Cobalt ferrite (Cofe2o4) particles were synthesized with and without presence of surfactants using a co-precipitation method. Three surfactants Cetyl Tri methyl Ammonium Bromide (CTAB-cationic), Sodium dodecylbenzenesulphonate (anionic), Triton X-100 (nonionic), were used and investigate their effects on the structural and dielectric properties of CoFe2O4 particles. The ferrite precursors were first pre calcined in a muffle furnace at 500°C and then calcined at 950° C. Structural, dielectric and magnetic properties of prepared particles were investigated using X-ray powder diffraction, Dielectric and Low field ac magnetic susceptibility measurement. Phase purity of prepared samples was confirmed by X-ray diffraction. The sample with surfactant Triton X-100 shows the highest values of dielectric constant at low frequency. Introduction The spinel ferrites are generally described by formulae such as MxFe3-xO4 in which M represents a transition metal [1]. Spinel ferrites have been investigated in recent years because of their high electrical resistivity, chemical stability, mechanical hardness and reasonable cost [2-5]. Most fascinating applications include antenna rod, transformer core, recording head, loading coil, memory and microwave devices, etc [6]. These are also useful to prevent and eliminate radio frequency interference to audio systems. Inverse spinel ferrites such as CoFe2O4, NiFe2O4, MnFe2O4 and CuFe2O4 showed ferrimagnetisms with high coercivity and moderate magnetization. CoFe2O4 is suitable material for developing new technologies in the areas of strategic importance [7-9]. CoFe2O4, are well known hard magnetic materials with very high cubic magneto crystalline anisotropy, high coercivity, and moderate saturation magnetization. These properties make it a promising material for high density magnetic storage. The systems made up of nanoparticles are intensively studied both theoretically and practically due to their electric, dielectric and magnetic properties that are sensibly different from those of the bulk materials and their possible applications in various fields [10]. These nanoparticles can be obtained by precipitation of metallic salts in different media as polymers, organic acid or alcohol, sugars etc., to ensure their colloidal stability, physiological condition and enhanced functionality. The size range depends on the precursors, surfactants and salts [11]. Surfactants (cationic, anionic and non-ionic) are amphiphilic materials containing a polar long- chain hydrocarbon “tail” and a polar, usually ionic “head” [12]. It can play an important role in synthesizing the material in different interesting morphologies. They may be used to control the size, shape and agglomeration among the particles. The coating of Surfactant on ferrite particles serves as a protective layer that prevents agglomeration of the particles, the oxidation of these nanoparticles from the atmospheric oxygen and minimizes the direct exposure of the ferrite surface to the biological environment [13, 14]. Ferrites have been synthesized using various methods such as solid state reaction, co-precipitation, micro emulsion, solvothermal, mechanosynthesis hydrothermal, sol–gel and combustion techniques. Co-precipitation method is a simple route to prepare fine, nano-crystallized, high-purity and homogeneous powders of single or multi- component oxides [15, 16]. Advanced Materials Research Vol. 938 (2014) pp 14-18 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.14
- 32. In present work, Co-precipitation method was used for the preparation of nanocrystalline CoFe2O4 with different surfactants and without surfactant. Effect of presence of surfactants on the particle size, microstructure, dielectric and magnetic properties of the resulting CoFe2O4 powders has been studied. Experimental Details Materials The reagents used in this experiment, Fe (NO3)3·9H2O, Co (No3)3·6H2O, and NaOH were of Analytical Grade. Triton X-100 (Non-ionic) and Cetyl Trimethyl Ammonium Bromide (CTAB, Cationic) of Analytical Grade and Sodium dodecylbenzenesulphonate (Anionic) of Purified Grade were used as a surfactant. All reagents were used without further purification. Double-distilled water was used throughout the experiment. Procedure 0.4M solution of Cobalt Nitrate (Co (No3)3·6H2O) and a 0.8M of Iron Nitrate (Fe (NO3)3·9H2O) solutions were mixed in double distilled water. The Fe3+ /Co2+ molar ratio in the solution is 2:1. A specified amount of surfactant was added to the solution as a coating material. 3M solution of sodium hydroxide was prepared and slowly added to the salt solution drop wise. The pH of the solution was constantly monitored as the NaOH solution was added. The reactants were constantly stirred using a magnetic stirrer until a pH level of 11-12 was reached. Ferrites are formed by conversion of metal salts into hydroxides, which take place immediately, and transformation of hydroxides into ferrites. These particles were filtered and washed several times with distilled water until the pH come to 7 followed by acetone. The solution was maintained at 80°C for 24 hours. This duration was sufficient for the transformation of hydroxides into spinel ferrite (dehydration and atomic rearrangement involved in the conversion of intermediate hydroxide phase into ferrite). The acquired substance was then grinded into a fine powder. At this stage the product (CoFe2O4) contains some associated water, which was then removed by preheating at 500°C for 4 hours which was then calcined at 950°C for 4 hours. Characterization Phase identification of the composite powders was carried out by a Philips diffractometer (PW 1830) using CuKα radiation (λ=1.5405 Ǻ) with a step scan 0.02ºC/min. The dielectric measurements were carried out at room temperature in a frequency range of 20 Hz to 2MHz using inductance capacitance resistance Meter Bridge (An Agilent E4980A precision LCR meter). Temperature dependent ac magnetic susceptibility measurements were performed with a magnetic field of 10 Oe in the range from room temperature to 600 o C. 0.5 – 1.0 cm3 of powder was used for the measurement. Result and Discussion XRD Analysis. Fig. 1 shows the X-ray diffraction patterns of calcined powders synthesized without surfactant and with different surfactants. Analysis of the diffraction patterns reveals the formation of single phase CoFe2O4 spinel ferrite without the traces of unreacting ambiguous reflections. The strongest reflection comes from the (3 1 1) plane denotes the spinel phase. The calculated lattice parameters (Table 1) are in close agreement with the standard JCPDS file PDF # 22-1086. The approximated crystallite size was determined by Scherrer formula using maximum intensity peak (3 1 1). Advanced Materials Research Vol. 938 15
- 33. D= . (1) Where, λ is wavelength of X-ray used in Ǻ, β is FWHM in radian and θ is Bragg angle. The intensities of peaks for the sample with CTAB are high, which indicate higher crystallinity [17] and slight increase in crystallite size is also observed with cationic surfactant CTAB. With anionic (Sodium dodecylbenzenesulphonate) and nonionic (Triton X-100) surfactants crystallite size is decreased. Non-ionic surfactant Triton x-100 is not ionized in water and has good stability, which leads to a better morphology of nanocrystalline than that of nanocrystalline prepared with other ionic surfactant. Therefore, the nanocrystalline prepared with Triton x-100 is much smaller, which indicates that molecular weight has great influence on the crystallite size. Fig. 1. XRD patterns of CoFe2O4 (a) Standard CoFe2O4 (b) Pure CoFe2O4 (c) CoFe2O4 with surfactant CTAB (d) CoFe2O4 with surfactant Sodium dodecylbenzenesulphonate (e) CoFe2O4 with surfactant Triton X-100. Table 1. d-spacing, FWHM and approximated Crystallite size Dielectric Analysis. Fig. 2 shows the variation of dielectric constant (є’ and є”) and loss factor (tan δ) as a function of frequency in the range 20 Hz to 2 MHz at room temperature for CoFe2O4 synthesized without surfactant and with different surfactants. It can be observed that all the samples exhibit dielectric dispersion where both real and imaginary dielectric constant decreases rapidly Sample Lattice constant (a) A° d(nm) FWHM XS (nm) Pure CoFe2O4 8.3649 0.25146 0.147 77 CoFe2O4 with surfactant CTAB (cationic) 8.3772 0.25181 0.139 86 CoFe2O4 with surfactant Sodium dodecylbenzene-sulphonate (anionic) 8.3744 0.25181 0.170 60 CoFe2O4 with surfactant Triton X-100 (nonionic) 8.3780 0.25315 0.180 55 16 Nanomaterials: Science, Technology and Applications
- 34. with increasing frequency in low-frequency region while it approaches almost frequency independent behaviour in high frequency region. Fig. 2. Variation of dielectric constant (є’ and є”) and loss factor (tan δ) as a function of frequency The polarization decreases with increase in frequency and then reaches a constant value due to the fact that beyond a certain frequency of external field, the electron exchange between Fe2+ and Fe3+ cannot follow the alternating field. The large value of dielectric constant at lower frequency is due to the predominance of species like Fe2+ ions, interfacial dislocations pile ups, oxygen vacancies, grain boundary defects, etc. [18], However the decrease in dielectric constant with frequency is natural because of the fact that any species contributing to polarizability lag behind the applied field at higher and higher frequencies. The sample with surfactant Triton X-100 shows the highest values of ε’ and ε’’ at low frequency. The increase in dielectric constant is due to decrease in grain size with addition of Triton X-100. When grain size is decreased, the resistivity increases and hence dielectric constant is increased. Low field ac magnetic susceptibility. Low field ac magnetic susceptibility measurements on prepared samples were carried out from room temperature to 600° C. The variations of magnetic susceptibility with temperature for all the samples are shown in Fig. 3. Fig. 3. Variation of ac magnetic susceptibility with Temperature Advanced Materials Research Vol. 938 17
- 35. From temperature dependent magnetic susceptibility measurement, Single domain (SD) states were observed for all the samples. In SD region, susceptibility increases and shows maxima at blocking temperature and drops sharply at Curie point. It is clear from the Fig. 3 that the sample with Sodium dodecylbenzenesulphonate surfactant showed high curie temperature and Triton X-100 added sample showed minimum curie temperature. Summary Cobalt ferrite (Cofe2o4) particles synthesized using co-precipitation method. Prepared powder characterized by XRD, Dielectric and Low field ac magnetic susceptibility measurement. XRD analysis confirms formation of spinel ferrite phase. The decrease in grain size of the sample with surfactant Triton X-100 shows the increase in dielectric constant. Acknowledgement This work was carried out under DRS-SAP program of UGC, Physics Department, Gujarat University, Navrangpura, Ahmedabad 380 009, India. References [1] P.Tailhades et al. / Journal of Magnetism and Magnetic Materials 193 (1999) 148-151. [2] R. Peelamedu, C. Grimes, D. Agrawal, R. Roy, J. Mater. Res. 18 (2003) 2292. [3] A.K.M. Akther Hossain, M. Seki, T. Kawai, H. Tabata, J. Appl. Phys. 96 (2004) 1273. [4] A. Goldman, Handbook of Modern Ferromagnetic Materials, Kulwer Academic Publishers, Boston, USA, 1999. [5] R. Valenzuela, Magnetic Ceramices, Cambridge University Press, Cambridge, 1994. [6] V.S. Kumbhar et al. / Applied Surface Science 259 (2012) 39 – 43. [7] R.Y. Hong, J.H. Li, X. Cao, S.Z. Zhang, G.Q. Di, H.Z. Li, D.G. Wei, J. Alloys Compd. 480 (2009) 947. [8] R. Skomski, J. Phys.: Condens. Matter 15 (2003) R1. [9] R.C. Kambale, P.A. Shaikh, N.S. Harale, V.A. Bilur, Y.D. Kolekar, C.H. Bhosale, K.Y. Rajpure, J. Alloys Compd. 490 (2010) 568. [10] I.H. Gul et al. / Journal of Magnetism and Magnetic Materials 320 (2008) 270–275. [11] Digest Journal of Nanomaterials and Biostructures Vol. 6, No 4, October-December 2011, p. 1783-1791. [12] A. Dominguez, A. Fernandez, N. Gonzalez, E. Igleslas and L. Montenegro, J. Chem. Ed. 74, (1997) 1227. [13] M. Ahmed, N. Okasha, et al., Journal of Alloys and Compounds 496 (2010) 345–350. [14] Maaz et al. / Journal of Magnetism and Magnetic Materials 308 (2007) 289–295. [15] Z. Zhong, et al., Powder Technology 155 (2005) 193–195. [16] S. Briceno et al. /Journal of Magnetism and Magnetic Materials 324 (2012) 2926–2931. [17] G.B. Ji et al. / Journal of Crystal Growth 270 (2004) 156–161. [18] J.C. Maxwell, Electric and Magnetism, Oxford University Press, New York, vol. 2, p.828, 1973. 18 Nanomaterials: Science, Technology and Applications
- 36. Modified Sol-gel production of Nano SDC20 Materials S. Ramesh1, a , K.C. James Raju2,b and C. Vishnuvardhan Reddy3,c 1,2 School of Physics, University of Hyderabad, A.P., India 3 Department of Physics, Osmania University, Hyderabad, A.P., India a ramesh.ou1@gmail.com (corresponding author), b kcjrsp@uohyd.ernet.ac.in, c reddycvv@osmania. ac.in Keywords: Sol-gel process, Nano crystalline, XRD, Rietveld, TEM Abstract. The production of high purity samarium doped ceria (SDC20, Sm0.2Ce0.8O2-δ) nanopowders by modified sol-gel process using maltose and pectin as organic precursors. Around, 6 nm particle size can be obtained after calcination of the as synthesized (pre dried) gel at 500 o C for 2 h. Rietveld refinement of Powder X-ray diffraction (XRD) patterns confirms the cubic structure with single phase. Chemical composition of SDC20 is in good agreement with EDX measurements. TEM and XRD analysis indicate the influence of sintering temperature on particle size, which increases with increasing temperature. This modified sol-gel process is a non-toxic and environmentally friendly for large-scale production of high purity nanopowders. Introduction In recent years, solid oxide fuel cells (SOFCs) have been attracting more attention because of their ability to provide clean, green and high efficiency energy conversion [1]. However, major constraint is the selection of materials for commercial SOFC, which are operated over a temperature of 1000 o C. Performance of SOFC depends on electrolyte materials. SOFC electrolyte should have high ionic conductivity, high chemical stability and high density etc., SOFC components made up of nanopowders have advantage like an electrolyte component may exhibit a finer grain structure and therefore a higher density of grain boundaries. Nanopartcles are active to heat transfer and have higher rate of densification at lower sintering temperature as a result of high surface area. These features may increase the oxygen ion mobility and therefore the ionic conductivity reducing ohmic losses in an electrochemical cell [2]. There are many routes to synthesize SDC20 nanopowders such as sol-gel process [3], ethylene glycol [4], and using ammonium nitrate [5]. Infact, it is important to use modified chemical method over existing one to improve the SDC20 particles more easily and cost effective manner. In the present study, a modified sol-gel process first proposed by Suci et al. [6] simple maltose and pectin are used as chelating and gelating agents to produce high purity SDC20 nanopowders. The obtained nanopowders are characterized using XRD, TEM, FE-SEM and EDX. Experimental SDC20 (Sm0.2Ce0.8O2-δ) composition was synthesized through modifies sol-gel process. Cerium nitrate hexa hydrate Ce (NO3)3 6H2O,(Alfa acer, 99.8% purity) and samarium nitrate hexa hydrate Sm (NO3)3 6H2O (Alfa acer, 99.8% purity) were used as starting materials. Samarium and cerium nitrates were calculated based on stoichiometry, and weighed accurately. Commercial grade maltose and pectin, Finar made, were used for gel preparation and mixed in mass ratio maltose: pectin = 50:1. Maltose made from glucose and fructose units, also known as ordinary table sugar. Pectin is present in ripe fruits and some vegetables. Pectin is widely used in food industry as gelating agent. Pectin consists of 300 and 1000 monosaccharide units [6,7]. Advanced Materials Research Vol. 938 (2014) pp 19-23 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.19
- 37. Fig. 1 Flow chart of modified Sol-gel process As shown in Fig.1 step1: maltose and pectin in the mass ratio 50:1 are mixed with distilled water in beaker until clear solution formation and labeled as a solution A. Step 2: cerium and samarium nitrates are dissolved in distilled water, stirred properly to get clear solution and labeled as solution B. The cationic concentration of solution B was controlled to 20 g L-1 of the final SDC20 composition. Step 3: solution A and solution B are mixed by dripping solution A into Solution B under continuous stirring for 2 h. The aim of this treatment is to prevent agglomeration of the constituent particles and to avoid solidification of the particles or raw granular formation during the different stages of processing. Maltose is made from one unit of α-glucose and β-fructose each. These two units in chains are linked by a β-glycosidic bond, which is a covalent bond between two monosaccharides that involves carbon C1 (anomeric) of the glucose and carbon C2 of the fructose. According to wang et al. [7], the electronegative O atom present in glucose or fructose ring structure in C1-C5 or C1-C4 carbon atoms and in C1-C4 β-glycosidic link per unit formula of maltose gains a partial negative charge, which enables the Ce3+ and Sm3+ cations. Ce3+ and Sm3+ cations are kept at a distance by the large pectin molecule, those consist 300-1000 monosaccharide units that form gelation of matrix structure hosting these cations. This is very important to control the large crystals formation during the subsequent calcinations stage. This is very essential step to form nano crystalline SDC20 solid solution. The homogeneous mixed solution was dried in a beaker at 80 o C on magnetic stirrer warm plate at constant stirring until the gel formation. The obtained gel was placed in a separate beaker and dried it keeping on warm plate at 90 o C for more than 20 hours until it became completely gelatinized and results light yellow powders. Further, as synthesized powders were calcined at 500 o C, 650 o C, 750 o C and 950 o C for 2 hours. The resultant ash was ground in agate mortar to get a fine homogeneous powder. XRD patterns of the samples were obtained by BRUKER D8 ADVANCED using Cu Kα radiation in the Bragg’s angle range of 20o ≤ 2θ ≤ 80o at room temperature. Fullprof Rietveld refinement software was used to analyze crystal structure. The calcined powders images were taken using the scanning electron microscope ZEISS (FE-SEM) equipped with an energy dispersive X-ray 20 Nanomaterials: Science, Technology and Applications
- 38. spectrometer (EDX) analyzer. Transmission electron microscopy images were taken from FEI, Technai20 G2 Stwin, G2083 model with Gatan CCD detector. Results and discussion XRD analysis The Fig. 2 shows XRD patterns of SDC20. There are no extra peaks, when Sm doped into CeO2. This confirms the formation of single phase and it contains only a cubic [8,9,10] structure with the space groupFm3m . Fig. 3 shows the Rietveld refinement of SDC20 sample using cubic #225 Fm3m space group. The Rietveld refinement was carried by FULLPROF program [11]. The rietveld parameters are shown in Table 1. The angular dependence of the peak full width at half maximum (FWHM) was described by Caglioti’s formula. Peak shapes were described by the pseudo-Voigt profile function. The background variation was described by a polynomial with six coefficients. All atom positions are fixed by the symmetry of the Fm3m space group and were not refined. Rare earth and alkaline earth cations are situated at the 4a site with the atomic coordinate (0 0 0) and oxygen is at the 8c site corresponding to the (0.25 0.25 0.25) position. Table 1. Crystallographic information SDC 20 Structure: Cubic Space group: Fm3m 500 o C 750 o C 950 o C Rp 5.04 5.45 4.99 Rwp 6.49 7.01 6.94 Rexp 7.45 7.40 6.74 GOF 0.87 0.94 0.97 Bragg R-factor 0.828 3.35 2.28 Rf factor 0.587 2.52 2.95 a(A°) 5.42125 (49) 5.42310 (25) 5.42484 (18) V (A°3 ) 159.330 (0.025) 159.494 (0.013) 159.647 (0.009) Density (g/cm3) 7.176 7.166 7.162 Crystallite size (nm) 6 (2) 12.1(3) 49.5(2) There is no difference in peak position between calcined and sintered samples except decrease in broadening (peak width) of peaks; they became relatively sharper and narrow. This indicates the grain growth at higher temperatures. Crystallite size, Dc of the calcined powders was calculated from XRD line broadening (1 1 1) reflection using Scherrer’s formula 0.9 cos c D λ β θ = where λ is the wavelength of X-ray radiation, β is the full width at half maximum (FWHM) after correcting the instrumental broadening, and θ is Bragg angle. The average crystallite was in the range 6 - 49.2 nm when the powder calcined at different temperatures (figure 2, Table 1). Particle size of calcined powder obtained from XRD is smaller than the average grain. Advanced Materials Research Vol. 938 21
- 39. Fig. 2 XRD patterns of SDC 20 Fig. 3 Rietveld refinement of SDC 20 at 500 o C and Fig. 4 TEM image of SDC20 powder at (a) 950 o C and (b) 500 o C Fig 4 shows TEM images of SDC20. It is noticed from the Fig. 4 that there is homogenously distributed SDC20 particles relatively uniform shapes and narrow size distribution. The ring patterns in the selective area electron diffraction (SAED) image of the represents the polycrystalline nature of sample (Inside figures of figure 4 and also HRTEM images). It can be seen that change of size of the particles with calcination temperature, it means size increased with temperature. These results are in good agreement with XRD studies 20 30 40 50 60 70 80 2θ (Degree) Intensity (Arb. Units) 500 o C 650 o C 750 o C 950 o C (420) (331) (400) (222) (311) (220) (200) (111) (a) (b) 500 o C 950 o C 22 Nanomaterials: Science, Technology and Applications
- 40. Conclusions The high purity SDC20 composition was successfully prepared by modified sol-gel process using maltose and pectin as organic precursors. Single cubic phase samarium doped ceria nano particles were successfully synthesized. In this, modified sol-gel production process, homogeneous distribution of metal ions and slow collapse of the carbohydrate structure during calcinations prevent the rapid agglomeration of metal ions, which ensures small particle size of the product. The electrical properties and sintering behavior of this material are currently being investigated and reported in near future. Acknowledgements The author, Dr. S. Ramesh is greatly acknowledging the UGC for providing the financial assistance under the DSKPDF scheme, Project No. F.4-2/2006(BSR)/13-389/2010 (BSR). References [1] H. Inaba and H.Tagawa, Ceria based solid electrolytes, Solid State Ionics, 83 (1996) 1-16. [2] B.C.H. Steele, Appraisal of Ce1−yGdyO2−y/2 electrolytes for IT-SOFC operation at 500°C, Solid State Ionics, 129 (2000) 95-110. [3] J. Van Herle, T. Horta, T. Kawada, N. Sakai, H. Yokokaya, M.Dokiya, Oxalate coprecipitation of doped ceria powder for tape casting, Ceramic International, 124 (1998) 229-241. [4] S. Ramesh, K.C. James Raju, C.V. Reddy, Properties of Al2O3-Sm2O3-CeO2 electrolyte, Trans. Nonferrous Met. Soc.China, 22 (2012) 1486-1494. [5] P.L. Chen, I.W.Chen, Reactive Cerium (IV) Oxide Powders by the Homogeneous Precipitation Method, J.American Ceramic Society, 76 (1993) 1577-1583. [6] C. Suciua, L. Gageab, A.C. Hoffmanna, and M. Moceanb, Sol–gel production of zirconia nanoparticles with a new organic precursor, Chemical Engineering Science, 61 (2006) 7831- 7835. [7] Z. Wang, G.M. Kale, M. Ghadiri, Maltose and pectin assisted sol–gel production of Ce0.8Gd 0.2O1.9 solid electrolyte nanopowders for solid oxide fuel cells, J. Mater. Chem., 21 (2011) 16494-16499. [8] S. Omer, E.D. Wachsman, Jacob L. Jones, and J.C. Nino, Crystal Structure–Ionic Conductivity Relationships in Doped Ceria Systems, J. Am. Ceram. Soc., 92 (2009) 2674- 2681. [9] S. Ramesh, K.C. James Raju, Structural and Ionic conductivity studies of doped ceria electrolyte, Electrochemical and Solid state letters, 15 (2012) B24-B26. [10] S. Ramesh, K.C. James Raju, Preparation and characterization of Ce1-x(Gd0.5Pr0.5)xO2 electrolyte for IT-SOFCs, International Journal of Hydrogen Energy, 37(2012) 10311 -10317. [11] J. Rodriguez-Carvajal, Recent advances in magnetic structure determination by neutron powder diffraction, Physica B, 192 (1993) 55-69. Advanced Materials Research Vol. 938 23
- 41. Effect of Heat treatment on Structural, Magnetic and Electric properties of Z- type Barium Cobalt Hexaferrite powder Neha Solanki1,a , Packiaraj G2,b and R. B. Jotania3,c 1,2,3 Department of Physics, University School of sciences, Gujarat University, Ahmedabad – 380009, Gujarat, INDIA. a nehashah2385@gmail.com, b packiaraj33@gmail.com, c rbjotania@gmail.com Key words: Z-type hexaferrite, sol-gel combustion technique, Structural analysis Abstract. Z-type hexaferrite with composition Ba3Co2Fe24O41 has been synthesized using a sol-gel auto combustion technique. The obtain combusted powder was sintered at 500 ᴼC and followed by 950 ᴼC for 4 hrs in a muffle furnace. The effect of different sintering temperature on crystal structure, crystallite size, microstructure and dielectric properties were systematically investigated. The prepared barium cobalt hexaferrite powder samples were characterized using different experimental techniques like FTIR, XRD, AC conductivity and specific magnetization measurements. It was observed from XRD results that heat treatment conditions play significant role in the formation of hexaferrite phase. AC conductivity measurements were carried out at room temperature in frequency range of 20Hz to 2MHz. All the samples show the frequency dependent phenomena, i.e. the AC conductivity increases with increasing frequency. Introduction Among the planar hexagonal ferrites discovered between 1952 and 1956 by Philips were Y ferrite (Ba2M2Fe12O22), W ferrite (BaM2Fe16O27) and Z ferrite (Ba3M2Fe24O41, Where M represents divalent metal ions) [1, 2]. Among all hexaferrites Co2Z (M=cobalt (II)) has a much higher permeability, dielectric constants, ferromagnetic resonance up to 1.5–3.4 GHz and a high thermal stability due to its high Curie point of 400 ᴼC [3]. Co2Z is used as soft materials, in the manufacture of multi-layer chip inductors (MLCIs), for high-frequency application such as LC filters and megahertz–gigahertz (MHz–GHz) antenna [4]. Z-type hexaferrite possesses planar hexagonal structure [5]. The unit cell is made up of S, R and T blocks and the divalent and trivalent metallic ions are distributed among ten different lattice sites [6]. This structure is considered as a stack of six kinds of blocks with stacking order is RSTSR*S*T*S* [7, 8] (Fig 1 (a, b)), where the asterisk indicates the same R, S, and T stack but rotated 180° around the c-axis. High temperature (1300 ᴼC) is requiring for sintering Z-type hexaferrite by the conventional ceramic method [9]. The main disadvantage of this method is it produces coarser particles. However several wet chemical methods such as hydrothermal synthesis [10], combustion synthesis [11, 12], sol–gel technique [13], citrate method [14, 15] and chemical co-precipitation method [16] require low sintering temperature. Sol-gel combustion synthesis route has some advantages like low sintering temperature, good homogeneity, high product purity crystallinity, fine particle size, narrow particle size distribution, less preparation time, inexpensive products [17, 18]. In present paper, we report effect of heat treatment on structural, electric and magnetic properties of Z-type Ba3Co2Fe24O41 hexaferrite powder prepared by sol-gel auto combustion technique. Advanced Materials Research Vol. 938 (2014) pp 24-29 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.24
- 42. Fig. 1. (a) Basic layers of a hexagonal ferrite and (b) crystal structure of Co2Z hexaferrite [8] Experimental details Synthesis of polycrystalline Ba3Co2Fe24O41 hexaferrite powder. Analytical grade Barium Nitrate [Ba(NO3)2], Cobalt Nitrate [Co(NO3)2], Ferric Nitrate [Fe(NO3)2] and Citric Acid [C6H8O7·H2O] were used as starting materials to prepare hexaferrite samples. The stoicheometric amount of metal nitrates and citric acid (molar ratio 1:1) was first dissolved one by one in to deionized water and kept on a magnetic stirrer under constant stirring. The Ammonia solution (30 % v/w) was slowly added in mixed solution to adjust pH-7. The prepared solution was heated at 80 ᴼC on a hot plate and stirred continuously till it transformed into a thick gel. At a proper temperature ignition started and thick dried gel burnt in a self-propagating combustion to form a fluffy loose powder. Finally, the as-burnt powder was calcined at 500 ᴼC and followed by 950 ᴼC for 4 hrs in a muffle furnace then slowly cooled to room temperature to obtain Ba3Co2Fe24O41 hexaferrite powder. Characterization. The effect of temperature on the formation of Ba3Co2Fe24O41 has been investigated by FTIR and XRD analysis. X-ray diffraction data were recorded on a Rigaku powder X-ray diffractometer using Cu-Kα radiation (λ =1.54056 Å) at 30.0 kV and 15.0mA in the region of 2θ = 20–80ᴼ. The crystalline phases were identified using X-ray diffraction. To confirm the formation of Barium Cobalt ferrite and to understand the nature of the residual carbon in the samples the FTIR spectra were recorded on a FTIR spectrometer (Bruker Tensor 27) at room temperature using the KBr pellet method between wave number ranges 4000-400 cm-1 . The dielectric measurements were carried out at room temperature in a frequency range of 20 Hz to 2MHz using inductance capacitance resistance meter bridge (An Agilent E4980A precision LCR meter). Low field specific magnetization measurements were performed with a magnetic field of 10 Oe in the range from room temperature to 600 ᴼC for different calcined samples. Results and Discussion: XRD Analysis. Fig. 2 shows the XRD pattern of burnt powder and calcined (at 500 ᴼC and 950 ᴼC for 4 hrs.) Ba3Co2Fe24O41 hexaferrite powder samples. All XRD peaks were indexed using powder- X software. The XRD peaks position and intensity of diffraction lines were compared with standered JCPDS-file no.19-0097. It is clear from figure 2 that as burnt powder and sample heated 500 ᴼC contain three different phases of CoFe2O4, α-Fe2O3, Ba3Fe2O6. At 950 ᴼC, well crystalline hexaferrite phases of Ba3Co2Fe24O41, Ba2Co2Fe12O22 were obtained. The crystallinity was found to enhanced in hexaferrite sample calcined at 950 ᴼC for 4 hrs. which is shown in Table. 1. Advanced Materials Research Vol. 938 25
- 43. Fig. 2. XRD patterns of Ba3Co2Fe24O41 as burnt sample and sintered at 5000 and 9500 C. Table. 1. Crystallite Size of Ba3Co2Fe24O41 as burnt sample and sintered at 5000 and 9500 C. Samples 2θ (degree) FWHM (degree) Crystallite Size (nm) Combusted 35.580 0.309 27 Heated at 500 ᴼC 35.540 0.301 28 Preheated + Heated at 950 ᴼC 33.940 0.254 33 FTIR Analysis. Fig. 3 shows FTIR spectra of as-burnt powder, powder preheated at 500 ᴼC and post heated at 950 ᴼC for 4hrs in wave number ranges of 400 - 4000 cm-1 . As burnt powder shows broad absorption peak between 3200- 3600 cm-1 and around 2500 cm-1 , these are due to stretching of O-H bond. First absorption peak is disappeared in the sample pre heated at 500 ᴼC as well as in the sample post heated at 950 ᴼC, while second peak still remain in the sample preheated at 500 ᴼC but not appear in post heated sample calcined at 950 ᴼC. The multiple bands around 1450 cm-1 in as burnt powder and preheated sample are due to stretching of C=C vibration. The bands appear at 460 cm−1 and at 510 cm−1 are due stretching of Fe–O vibration. 26 Nanomaterials: Science, Technology and Applications
- 44. Fig. 3. FTIR spectra of Ba3Co2Fe24O41 as burnt sample and sintered at 5000 and 9500 C. Low field specific magnetization measurement. Low field specific magnetisation measurements on prepared samples were carried out from room temperature to 600 ᴼC. The variations of specific magnetisation with temperature for all the samples are shown in Fig. 4. It is clear from Fig. 4 that preheated sample followed by post calcined hexaferrite powder show low value of specific magnetization compared to as burnt powder sample and preheated sample. However, Hopkinson peaks are found to broaden for both as burnt as well as preheated samples. It may be attributed to a wide distribution of the particles shape [19]. Fig. 4. Specific magnetization curve AC conductivity measurements. AC conductivity of prepared samples was calculated from the data of dielectric constant (ε′) and loss, tangent (tan δ) using the relation Advanced Materials Research Vol. 938 27
- 45. σac = ε′ εo ω tan δ (1) Where εo is the vacuum permittivity and ω = 2πf is the angular frequency. Fig. 5. The variation of AC Conductivity with Log Frequency The variations of AC conductivity (σac) with Log f for all three samples are shown in Fig. 5. It is clear from Fig. 5 that AC conductivity of as burnt powder and preheated sample increase fast with increase of frequency (> 500 Hz), while there is not much change in value of ac conductivity for the sample calcined at 950 ᴼC (Preheated followed by calcination). The frequency dependence of conductivity can be explained with the help of Maxwell Wagner two-layer model [20-21]. According to this theory, two layers are formed in dielectric structure. The first layer consists of ferrite grains of fairly well conducting, which is separated by a thin layer of poorly conducting substances, which forms the grain boundary. These grain boundaries are more active at lower frequencies; which act as a hindrance for mobility of the charge carriers [22], hence the hopping frequency of electron between Fe3+ and Fe2+ ion is less at lower frequencies. As the frequency of the applied field increases, the conductive grains become more active by promoting the hopping of electron between Fe3+ and Fe2+ ions, thereby increasing the hopping frequency. So, we observe a gradual increase of conductivity with frequency [23, 24]. The linear increase in ac conductivity with the frequency confirms the polaron type of conduction [25]. Summary Z-type hexaferrite powder with composition Ba3Co2Fe24O41 synthesized using a sol-gel auto combustion method. Prepared powder characterized using various FTIR, XRD, specific magnetization measurement and electrical conductivity measurements. XRD analysis confirms formation of hexaferrite phase in the sample preheated followed by 950 ᴼC calcinations. AC 1 2 3 4 5 6 0.0 1.0x10 -5 2.0x10 -5 3.0x10 -5 4.0x10 -5 5.0x10 -5 AC Conductivity (mho/cm) Log F As burnt Powder Heated at 500 0 C Preheated + Heated at 950 0 C 1.5 2.0 2.5 3.0 3.5 4.0 0.0 2.0x10 -7 4.0x10 -7 6.0x10 -7 8.0x10 -7 1.0x10 -6 AC Conductivity Log F 28 Nanomaterials: Science, Technology and Applications
- 46. conductivity found to increase with increase of frequency explained by using Maxwell-Wegner two layer model. Acknowledgement This work was carried out under DRS-SAP programme of UGC, Physics Department, Gujarat University, Navrangpura, Ahmedabad 380 009, India. References [1] J.J. Went, G.W. Rathenau, E.W. Gorter, G.W. Van Oosterhaut, Phil. Tech. Rev. 13 (1952) 194. [2] H. Jonker, H.P. Wijn, P.B. Braun, Phil. Tech. Rev. 18 (1956) 154. [3] J. Smit, H.P.J. Wijn, Ferrites, Philips Technical Library, Eindhoven, 1956, pp. 204–207. [4] X.H. Wang, L.T. Li, S.Y. Su, Z.L. Gui, J. Am. Ceram. Soc. 88 (2005) 478–480. [5] J.J. Xu, C.M. Yang, H.F. Zou, Y.H. Song, G.M. Gao, B.C. An, S.C. Gan, J. Magn. Magn. Mater. 321 (2009) 3231–3235. [6] G. Albanese, Journal De Physique, Colloque C1, supplyment au no 4, Tome 38, Avril 1977, page C1-85. [7] L. Jia, Y. Tang, H. Zhang, P. Deng, Y. Liu, B. Liu, Jpn. J. Appl. Phys. 49 (2010) 063001. [8] K. Kamishima, J. Magn. Magn. Mater. 312 (2007) 228–233. [9] M. R.Barati, J. Sol-Gel Sci. Technol. 52 (2009) 171–178. [10] X. Jiao, D. Chen, Y. Hu, Mater. Res. Bull. 37 (2002) 1583. [11] C. Hwang, J. Tsai, T. Huang, Mate. Chem. Phys., 110 (2005) 1-7. [12] C. H. Peng, C. Hwang, S. Chen, Mater. Sci. Eng. B 107 (2004) 295. [13] D. H. Chen, X. R. He, Mater. Res. Bull. 36 (2001)1369. [14] M. Mouallem-bahout, S. Bertrand, O. Pena, J. Solid State Chem. 178 (2005) 1080. [15] A. Verma, T. C. Goel, R. G. Mendiratta, J. Magn. Magn. Mater. 208 (2000) 13. [16] Q. Chen, A. J Rondinone, B. C. Chakoumakos, J. Magn. Magn. Mater. 194 (1999) 1. [17] B. L. Bischoff, M. A. Anderson, Chem. Mater. 7 (1995) 1772. [18] C. C. Wang, J. Y. Ying, Chem. Mater. 11 (1999) 3113. [19] V. J. árik, A. Grusková, J. Sláma, R. Dosoudil, A. González, G. Mendoza, Advances in Electrical and Electronic Engineering (2011) pp 344-346. [20] A. Katoch, A. Singh, International Journal of Enhanced Research in Science Technology & Engineering 2 (2013) 1-7. [21] A.K. Jonscher, Dielectric Relaxation in Solids, Chelsa Dielectrics, London, 1983. [22] M. Hashim , Ceram. Int. 39 (2013) 1807–1819. [23] M.A. El Hitti, J. Magn. Magn. Mater. 164 (1996) 187. [24] A.M.Bhavikatti, International Journal of Engineering Science and Technology 2(11) ( 2010) 6532-6539. [25] M. Penchal Reddy, W. Madhuri, G. Balakrishnaiah, N. Ramamanohar Reddy, K.V. SivaKumar, V. R. K. Murthy, M. Hashim, Ceram. Int. 39(2013)1807–1819. Advanced Materials Research Vol. 938 29
- 47. Kinetics of silver nanoparticle growth using DMF as reductant – Effect of surfactants Paramita Sarkar1,a , Chithra Parameswaran1,b , C Harish1,c , M Bhanu Chandra1,d and A Nirmala Grace1,e 1 Centre for Nanotechnology Research, VIT University, Vellore-632014, TamilNadu, India a paramitasarkar2@gmail.com, b chits.puthen@gmail.com, c chevva.harish@gmail.com, d mbhanu.iiit@gmail.com, e anirmalagrace@vit.ac.in Keywords: Silver Nanoparticles, Kinetics, Surfactants, Surface Plasmon Resonance, FWHM Abstract. Silver nanoparticles are synthesized using N,N dimethyl formamide (DMF) both as reductant as well as solvent. The reaction is performed in the presence and absence of surfactants at room temperature to know the effect of the same on the size and shape of the silver nanoparticles. In this regard, two different surfactants viz. polyvinylpyrolidone (PVP) and cetyl trimethyl ammonium bromide (CTAB) are used. The rate of the reaction and the formation kinetics is continuously monitored by UV-vis spectroscopy at regular time intervals. The corresponding change in plasmonic peaks and full width half maxima (FWHM) is studied in detail. The particle size is determined using Mie plot. Introduction Optical properties of noble-metal nanoparticles are amazing, with varied applications in many fields like optics and electronics due to their quantized motion of electrons known as plasmons. They give a sharp absorbance for a certain wavelength in the UV-Vis spectroscopy, termed ‘surface plasmon resonance’. The theory of surface plasmon band originates from the interaction of nanoparticles in solution or in solid phase with a particular frequency domain. This is due to collective resonance of conduction electrons specific of nanoparticles for their geometrical confinement effects of these free electrons. This absorption is also referred to as ‘Mie Resonance’, after one of its most prominent contributors Gustav Mie. The surface plasmonic band is observed for metallic nanoparticles bigger than 2nm. Gold, silver and copper nanoparticles exhibit highly intense bands making them prominent in this field. The position, shape and intensity of the absorption peak strongly depends on dielectric constant of the surrounding medium and electronic interaction between stabilizing ligands and the nanoparticle; these alter the electron density inside the particle and consequently their size, shape and monodispersity [2]. This phenomenon, modelled successfully by Mie theory holds good over more than 100 years. Several other models for the same are also appraised [3]. The optical properties of metallic nanoparticles have been exploited in the industry for a wide range of applications by their size and shape controlled synthesis. Among the various nanomaterials, silver nanoparticles have fascinated a plethora of interest in the scientific community due to their potential applications in areas such as nanoelectronics, optical filters, electromagnetic interference shielding, and surface-enhanced Raman scattering. Among the various solvents reported, DMF is one of the best candidates for the synthesis of silver nanoparticles and hence used here. The polymer, PVP, is chosen in view of its applications in diverse fields like catalysis, drug delivery, etc. PVP is a homopolymer having an individual unit containing an aprotic polar imide group. The oxygen atoms of the imide group has a strong affinity to silver cations supplying electrons to the silver cations, causing reduction and stabilization of the resulting silver particles through surface adsorption of the PVP chain. N CH2 CH n [ ] O PVP Advanced Materials Research Vol. 938 (2014) pp 30-35 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.30
- 48. The Reaction mechanism N, N-dimethyl formamide (DMF) is one of the common organic compounds used as a solvent for various reactions. The oxidation of DMF from hydrogen-water mixtures generates hydrogen gas [7]. DMF acted as a potent reducing agent for the reduction of Ni(IV) to Ni(II) in basic conditions, which shows that DMF could be used as an active reducing agent under suitable conditions[8]. Liz-Marzan et al investigated the synthesis of silver nanoparticles using DMF as solvent as well as reducing agent [9]. The mechanism of reducing silver ions by DMF is HCONMe2 + 2Ag+ + H2O → 2Ag0 + Me2NCOOH + 2H+ (1) This mechanism is supported by a measured increase of conductivity as the reaction proceeds, indicating that the larger Ag+ ions are progressively exchanged for the more mobile H+ ions. The carbamic acid decomposes to carbon dioxide as explained below [7]. Me2NCOOH → CO2 + Me2NH (2) A basic difference of this reaction from other reducing agents like alcohol is that the reaction proceeds at a meaningful rate even at room temperature [10]. Although many studies have been carried out in this area, some of the experimental details still remain unclear. Hence we have chosen this system to study the nature and growth of Ag nanoparticles at various reaction conditions. Several methods have been proposed. Here, chemical synthesis process is used, where reduction is initiated by solvated electrons generated from ionizing radiation and is advantageous as the reaction is carried out at room temperature and less time consuming. The reducing action of DMF is already studied [5], but the kinetic analysis is yet to be done. Here, we emphasise the kinetics of silver nanoparticles in the presence and absence of surfactants at room temperature. The kinetics was studied by UV-Vis spectrometry. It is one of the many techniques to obtain quantitative approximation of the plasmon peak, which is then exploited to precisely obtain particle size with the aid of Mie Plot software which holds good for spherical nanoparticles. The FWHM gives precise information on the particles size distribution and are evaluated manually from the mid-value of recorded data. Also, theoretical curve fittings are employed to analyse the dependence of the parameters on time and particle size. These are indicated by the black solid lines in the graphs shown in following discussion. The regression coefficient (R2 ) is a statistical parameter which reveals the extent of dependence of the ordinate variable on the abscissa. Materials and methods Materials Silver nitrate (AgNO3), Polyvinylpyrrolidone (PVP), Cetyl trimethylammonium bromide (CTAB) and N,N Dimethylformamide (DMF) were purchased from SD fine Chemicals. All the synthesis was carried out in double distilled water. Instrumentation UV-Vis Spectra are recorded using SpecordR 210 plus. The spectra were plotted using Microcal Origin (Version 6.0), and particle size was determined theoretically by the software MiePlot (Version 3.4.10). Synthesis of silver nanoparticles Synthesis of Ag nanopartricles using PVP 7mM AgNO3 and 20mM of PVP is added to 100ml of DMF under stirring at room temperature. The solution is kept under continuous stirring for 15mins. After a period of time, a yellow colour is formed. UV-Vis spectrum is recorded every 2mins. The same experiment is carried out without PVP as well. Synthesis of Ag nanoparticles using CTAB 7mM AgNO3 and 20mM of CTAB is added to 100ml of DMF under stirring at room temperature. The solution is kept under continuous stirring for 15mins. After a period of time, a yellow colour is formed confirming nanoparticle formation. UV-Vis spectrum was recorded every 2mins. Advanced Materials Research Vol. 938 31
- 49. Result and discussion Synthesis of silver nanoparticle in absence of surfactant at room temperature To know the role of surfactants, the reaction is carried out in absence of surfactant. The corresponding surface plasmon absorption spectra are shown in Fig. 1 for different time intervals. FWHM, SPR position and radius of the nanoparticle formed are estimated and a few values are listed in Table 1 Table 1 Statistical data Figure 1 UV-Vis spectrum Statistical Analysis Here the spectrum is centred at wavelengths between 426nm to 438nm and the particle size lies in the range 32nm to 37nm. Highest peak obtained at the starting point just after adding AgNO3 reveals nanoparticle formation and onset of reaction and its concentration increases as time elapses and saturates at a later point of time. Figure 2 SPR peak position dependence (a) Reaction Time and (b) Particle size Fig. 2(a) shows the fifth order dependence of SPR on reaction time by y = -5E-05x5 + 0.0031x4 - 0.0744x3 + 0.8176x2 - 4.368x + 437.5 with R² = 0.9518 and Fig. 2(b) shows its linear dependence by y = 2.4603x + 346.3 with R² = 0.9932 Figure 3 FWHM dependence (a) Reaction Time and (b) Particle size Fig. 3(a) shows fourth order dependence of FWHM on reaction time by y = 0.0008x4 - 0.0507x3 + 1.1461x2 - 11.378x + 169.04 with R² = 0.9888 and Fig. 3(b) shows its linear dependence on particle size by y = 10.333x - 212.45 with R² = 0.9542 Synthesis of silver nanoparticle in the presence of surfactant PVP at room temperature The absorbance spectrum of PVP stabilized silver colloids show peaks at around 420 nm pertaining to the plasmon absorption of spherical silver nanoparticles. The absorbance is recorded 15mins after the addition of silver nitrate to DMF as at this point pale yellow color confirms Time(mins) 0 2 10 20 26 SPR Position (nm) 438 430 428 426 426 FWHM(nm) 171 147 128 123 121 Particle Radius (nm) 37.3 34 33 32.5 32.5 300 400 500 600 700 0.0 0.2 0.4 0.6 0.8 1.0 26 m ins Absorbance (a.u.) W avelength (nm ) 0 m ins 32 Nanomaterials: Science, Technology and Applications
- 50. presence of silver nanoparticles and readings are reported as 0 to 72 minutes, where zeroth minute indicates the absorption immediately after 15mins of synthesis. The spectra gives plasmons centred at wavelengths between 413 nm to 423 nm, for which the particle size lies in the range 27 nm to 31 nm (theoretical). The initial peaks are broad due to the presence of small seeds and as time increases, the absorption intensity increases, indicating the formation of silver nanoparticles with time. 300 400 500 600 700 0.0 0.2 0.4 0.6 72 mins Absorbance (a.u) Wavelength(nm) 2 mins Figure 4 UV-Vis spectrum Statistical analysis The UV-Vis spectrum has a single peak at 420 nm showing the presence of spherical nanoparticles. A few estimated values are presented in Table 2. Figure 5 FWHM of surface Plasmon peak position dependence on (a)Reaction time and (b)Particle size Fig. 5(a) shows the fourth order dependence of FWHM on reaction time by y= -4E-0.6x4 +0.001x3 - 0.0866x2 +3.014x+382.6 with R2 = 0.9979 and Fig. 5(b) shows its linear dependence on particle size by y=5.274x-67.075 with R² = 0.9479 Figure 6. SPR peak position dependence (a) Reaction time and (b) Particle size Fig. 6(a) shows the linear dependence of SPR on particle size by y=2.3333x+350.19 with R2 = 0.9713. Fig. 6(b) shows its fourth order dependence on time by y = 3E-06x4 - 0.0006x3 + 0.0411x2 - 1.1536x+425.14 with R² = 0.9798 Synthesis of silver nanoparticle in the presence of surfactant CTAB CTAB showed no results at room temperature and also when heated. Hence, 0.01M NaBH4 is added. The solution changed pale Time (mins) 2 20 40 60 90 SPR Position (nm) 423 415 416 417 413 FWHM (nm) 97 81 80 79 76 Particle Radius(nm) 31 28 28.3 28.5 27.5 Table 2 Statistical data Advanced Materials Research Vol. 938 33
- 51. yellow on addition of 3 drops of the reductant. NaBH4, having very high reduction potential readily reduces the Ag+ ions to metallic silver giving silver nanoparticles. The plasmon resonance absorption spectra obtained are shown in Fig. 7. Here, the peak wavelengths centred in 424nm to 432nm. The absorption spectra are recorded as shown below. 300 400 500 600 700 0.2 0.4 0.6 0.8 1.0 16 mins Absorbance (a.u) Wavelength(nm) 0 mins Figure 7. UV-vis spectrum The FWHM, SPR peak at various time instants are tabulated in Table 3. The data given above were analysed by obtaining the graphs for FWHM and SPR Peak with Time and Particle Size. The graphs obtained are shown below. Figure 8 FWHM dependence (a) Reaction Time and (b) Particle size Fig. 8(a) shows the dependence of FWHM on reaction time by a fourth order polynomial y = -0.0057x4 + 0.6602x3 - 28.29x2 + 529.32x - 3519.1 with R² = 0.8957. Fig. 8(b) shows its linear dependence on particle size y = 11.907x - 251.59 with R² = 0.936. Figure 9. FWHM dependence (a) Reaction Time and (b) Particle size Fig. 9(a) shows fourth order dependence of SPR on time y = -0.0017x4 + 0.1917x3 - 8.1729x2 + 152.42x - 622.97 with R² = 0.9198 and Fig. 9(b) shows its linear dependence by y = 2.3164x + 350.96 with R² = 0.994 Conclusion: In this work, spherical particles of silver are obtained as characterised by the single plasmonic peak in the absorbance spectra. The reaction is monitored in the presence of two different surfactants viz. Time(mins) 20 24 30 34 40 SPR Position (nm) 425 429 428 432 424 FWHM(nm) 130 148 140 164 155 Particle Radius (nm) 32 33.7 33 35 31.5 Table 3 Statistical data 34 Nanomaterials: Science, Technology and Applications
- 52. PVP and CTAB. The effect of surfactants on the size distribution of particles obtained is investigated and it is found that CTAB is better than PVP in this regard. The distribution is very wide in absence of surfactant, and narrower distribution is observed for CTAB, than PVP. Particle of average size 33 nm is achieved with CTAB and for PVP it is 33.5nm. The reaction in presence of CTAB did not occur at room temperature but in presence of a strong reductant NaBH4 (0.01M). Hence, the actual function of CTAB in presence of DMF is yet to be explored. References [1] Asta Sileikaite, Judita Puiso, Igoris Prosycevas, Sigitas Tamulevicius, Material Science,(2009) 21-27 [2] Audrey Moores, Frederic Goettmann, New J.Chem., 30 (2006) 1121-1132 [3] Viktor Myroshnychenko, Jessica Rodroguez-Fernandez, Isabel Pastoriza-Santos, Alison M.Funston, Carolina Novo, Paul Mulvaney, Luis M Liz-Marza, F. Javier Garcia de Abajo, Chem. Soc.Rev., 37 (2008) 1792-1805 [4] Javed Ijaz Hussain, Sunil Kumar, Athar Adil Hashmi, Zaheer Khan, Adv. Mat. Lett. (2011) 188- 94 [5] Isabel Pastoriza Santos and Luis M. LizMarzan, Pure Appl. Chem., 72 (2000) 83-90 [6] Emil Roduner, Chem. Soc. Rev., 35 (2006) 583-592 [7] J.Y. Yu, S. Schreiner, L. Vaska, Inorg. Chim. Acta, (1990),170, 145. [8] G.H. Hugar, S.T. Nandibewoor, Ind. J. Chem., (1993), 32A, 1056. [9] I.P Santos, L.M. Liz Marzan, Langmuir, (2002), 18, 2888. [10] H. Hirai, Y. Nakao, N. Toshima, N. J. Macromol. Sci. Chem., (1979), A13, 727. Advanced Materials Research Vol. 938 35
- 53. Microstructure and adhesion properties of a-CN and Ti/a-CN nanocomposite thin films prepared by hybrid ion beam deposition technique P. Vijai Bharathy1 *, Q.Yang2 , D.Nataraj3 1 Department of Physics, CBM College, Kovaipudur, Coimbatore 2 Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada 3 Thin film and Nanomaterials Lab, Department of Physics, Bharathiar University, Coimbatore, India *(P.Vijai Bharathy) pvijay126@gmail.com Keywords – Titanium, carbon nitride, nanocomposite thin film, XPS, nanomechanical properties, Abstract Carbon based materials have attracted much for its unique surface microstructure and nanomechanical properties among researchers. In this study, the influence of microstructure on the nanomechanical properties of thin carbon based films was studied in detail. For which amorphous Carbon nitride (a-CN) and Titanium incorporated amorphous Carbon nitride (Ti/a-CN) thin films were prepared with a thickness of less than 100 nm using hybrid ion beam deposition technique. The incorporation of Ti into the a-CN matrix greatly modified the sp3 /sp2 hybridized bonding ratio and it is reflected in the mechanical hardness of Ti/a-CN thin film. Most of the incorporated Ti reacts with carbon and nitrogen to form TiN and TiCN phases respectively. On the other hand, owing to the usage of energetic ion bombardment and the presence of TiN/TiCN phases in the carbon nitride matrix, the Ti/a-CN nanocomposite film shows improved adhesion strength compared to that of pure a-CN film. Overall the presence of hard metallic phase in the amorphous carbon network alters the microstructure and improves the adhesion strength of a-CN films suitable for protective coating applications. Introduction Amorphous hydrogenated carbon thin films have been attracting much attentions for its high mechanical hardness, chemical inertness, high wear resistance and superior friction performance suitable as protective coating material for biomedical devices and automotive engine parts [1-2]. Liu and Cohen [3] have theoretically predicted that a film with high hardness as that of diamond, low compressibility and highly elastic fullerene like structures can be prepared by incorporating nitrogen into the amorphous carbon matrix. After that numerous growth methods such as plasma enhanced chemical vapour deposition (PECVD), vacuum cathodic arc method, magnetron sputtering, ion beam assisted deposition and pulsed laser deposition [1,4,5] have been used to incorporate nitrogen into diamond like carbon (DLC) matrix to form crystalline beta phase carbon nitride (β-C3N4) thin film. Most of the research works were focused on altering the combination of C-sp, C-sp2 and C-sp3 hybridized bonding fraction to increase the mechanical hardness of CN film equal to that of diamond. Only few researchers have observed an increase in the lubrication effect, low friction coefficient, increased biocompatibility and increased corrosion resistance [4-6] that too by controlling the deposition conditions. However, most of the attempts lead to graphitic a-CN thin film with poor adhesion strength and very low mechanical hardness with increase in nitrogen fractions. Thus, apart from altering the existing deposition conditions, incorporating metal or non- metal into the a-CN matrix is also an effective way to enhance the mechanical and tribological properties of a-CN films. In the present research work, a-CN thin film and titanium incorporated a-CN nanocomposite thin film were deposited at room temperature using hybrid ion beam deposition technique. To the best of our knowledge, no previous work has been reported on the fabrication of pure a-CN and Ti/a-CN nanocomposite thin films using the present hybrid deposition method. Also Advanced Materials Research Vol. 938 (2014) pp 36-39 © (2014) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.938.36
- 54. till now the role of titanium incorporation on the adhesion strength of a-CN film is not yet fully understood. We focused mainly on understanding the chemical reactivity and the adhesion strength of a-CN and Ti incorporated a-CN thin film. Experimental Procedure Amorphous Carbon nitride (a-CN) and Ti incorporated a-CN nanocomposite thin films were deposited onto the Si (100) substrate by using hybrid ion beam deposition technique. This hybrid deposition technique combines simultaneous deposition of carbon nitride film using ion beam deposition and titanium incorporation using ion beam sputtering. The detail working mechanism of the deposition system was explained elsewhere [7]. High purity methane and argon gases were mixed in the ratio of 1:1 and introduced into end hall ion source 1. Along with the hydrocarbon ion beam with ion energy 45 eV, high purity nitrogen gas (5 sccm) was introduced as back ground gas to deposit amorphous carbon nitride thin film. Similarly for the deposition of Ti/a-CN nanocomposite thin film, the hydrocarbon ion beam with ion energy of 45 eV mixed with nitrogen gas was directed towards the substrate to deposit a-CN film, at the same time titanium was sputtered by using Ar gas using another end-hall ion source II using the ion energy 45 eV. The Ti sputtering was carried out with the negative target bias voltage of -800 V. The other deposition parameters including the methane/argon, nitrogen gases ratio and ion beam energy from the ion sources were fixed to constant. The substrate holder was placed at an angle of 45o and rotated around its axis at a constant rate of 3 rpm to enhance deposition uniformity. In order to maintain the substrate temperature below 30o C, separate substrate cooling was provided. The deposition time was altered in accordance with the film thickness. The thickness of all the films was very close to 95 nm + 1 nm as measured by surface profilometer. The chemical composition and binding energies of a-CN and Ti/a-CN thin films were determined using X-ray photoelectron spectroscopy using VG Microtech multilab 3000 spectrometer. The mechanical hardness and elastic modulus of the films were measured using Nanoindenter [7,8]. The adhesion strength of the films was evaluated using scratch tester by applying a ramping load range from 0.1 N to 20 N at a distance of 5 mm in 30 sec. Results and Discussion X-ray Photoelectron spectroscopic (XPS) Analysis The chemical composition and bonding nature of pure a-CN and Ti/a-CN thin films were studied using XPS analysis. The relative elemental concentration of titanium in Ti/a-CN film is 6.2 at.% for − 800 V biased voltage and the atomic percentage of nitrogen is ~7.2 at.% approximately. Fig. 1 (a-b) shows the core-level C 1s and N 1s XPS spectra of as deposited pure a-CN thin film. It shows that the C 1s spectrum was composed of two central carbon peaks corresponding to nitrogen bonded C-sp3 (286.6 eV) and nitrogen bonded C-sp2 (285.5 eV) hybridized bonds. Additionally, two more peaks were observed at 284.5 eV and 287.3 eV corresponding to sp2 (C-C) and N-sp1 C atom, respectively. Similarly, Fig. 1b shows the de-convoluted N 1s core level XPS spectrum in- between the binding energy 397 eV to 402 eV. The N 1s spectrum was fitted with different binding energies like 398.6, 399.1, 400.2 and 401.9 eV which were attributed to nitrogen atoms bonded to sp3 C, sp1 C, sp2 C and N or O atoms, respectively. All these binding energies of different C 1s and N 1s peaks agree well with that of the previous literatures [7-9]. Fig. 1 (c-e) shows the deconvoluted C 1s, Ti 2p and N 1s core level XPS spectra of Ti/a-CN thin film. Both the de-convoluted C 1s and N 1s spectra of a-CN and Ti/a-CN thin films do not show much variation in the compositions of elemental bonding; however it shows a slight shift in the peak positions. This may be due to the incorporation of Ti into the a-CN matrix. On the other hand, many researchers suggested that based on the bonding fractions of sp3 C and sp2 C, the overall properties of the carbon based films can be observed [8, 9]. Thus, the sp3 /sp2 ratios were evaluated by using integrated areas of C 1s spectra for both a-CN and Ti/a-CN thin films. It was found that the sp3 /sp2 ratio decreases by incorporating Ti and which is 0.543 for pure a-CN and 0.392 for Ti/a-CN film which directly implies an increase in C-sp2 content. This clearly indicates a fact that by incorporating Ti, it starts to reacts with C atoms and thus breaks the C-C sp3 bonding to form C-C sp2 bonding in Ti/a-CN nanocomposite thin film. Advanced Materials Research Vol. 938 37
- 55. Another Random Document on Scribd Without Any Related Topics
- 56. Undershell (to himself). Alone with a lovely girl, who has no suspicion, as yet, that I am the poet whose songs have thrilled her with admiration! Could any situation be more romantic? I think I must keep up this little mystification as long as possible. Phillipson (to herself). I wonder who he is. Somebody's Man, I suppose. I do believe he's struck with me. Well, I've no objection. I don't see why I shouldn't forget Jim now and then—he's quite forgotten me! (Aloud.) They might have sent a decent carriage for us instead of this ramshackle old summerhouse. We shall be hours getting to the house at this rate! Und. (gallantly). For my part, I care not how long we may be. I feel so unspeakably content to be where I am. Phill. (disdainfully). In this mouldy, lumbering old concern? You must be rather easily contented, then! Und. (dreamily). It travels only too swiftly. To me it is a veritable enchanted car, drawn by a magic steed. Phill. I don't know whether he's magic—but I'm sure he's lame. And I shouldn't call stuffiness enchantment myself. Und. I'm not prepared to deny the stuffiness. But cannot you guess what has transformed this vehicle for me—in spite of its undeniable shortcomings—or must I speak more plainly still? Phill. Well, considering the shortness of our acquaintance, I must say you've spoken quite plainly enough as it is! Und. I know I must seem unduly expansive, and wanting in reserve; and yet that is not my true disposition. In general, I feel an almost fastidious shrinking from strangers—— Phill. (with a little laugh). Really, I shouldn't have thought it! Und. Because, in the present case, I do not—I cannot—feel as if we were strangers. Some mysterious instinct led me, almost from the first,
- 57. to associate you with a certain Miss Maisie Mull. Phill. Well, I wonder how you discovered that. Though you shouldn't have said "Miss"—Lady Maisie Mull is the name. Und. (to himself). Lady Maisie Mull! I attach no meaning to titles— and yet nothing but rank could confer such perfect ease and distinction. (Aloud.) I should have said Lady Maisie Mull, undoubtedly— forgive my ignorance. But at least I have divined you. Does nothing tell you who and what I may be? Phill. Oh, I think I can give a tolerable guess at what you are. Und. You recognise the stamp of the Muse upon me, then? Phill. Well, I shouldn't have taken you for a groom exactly. Und. (with some chagrin). You are really too flattering! Phill. Am I? Then it's your turn now. You might say you'd never have taken me for a lady's maid! Und. I might—if I had any desire to make an unnecessary and insulting remark. Phill. Insulting? Why, it's what I am! I'm maid to Lady Maisie. I thought your mysterious instinct told you all about it? Und. (to himself—after the first shock). A lady's maid! Gracious Heaven! What have I been saying—or rather, what haven't I? (Aloud.) To—to be sure it did. Of course, I quite understand that. (To himself). Oh, confound it all, I wish we were at Wyvern! Phill. And, after all, you've never told me who you are. Who are you? Und. (to himself). I must not humiliate this poor girl! (Aloud.) I? Oh —a very insignificant person, I assure you! (To himself.) This is an occasion in which deception is pardonable—even justifiable!
- 58. Phill. Oh, I knew that. But you let out just now you had to do with a Mews. You aren't a rough-rider, are you? Und. N—not exactly—not a rough-rider. (To himself.) Never on a horse in my life!—unless I count my Pegasus. (Aloud.) But you are right in supposing I am connected with a muse—in one sense. Phill. I said so, didn't I? Don't you think it was rather clever of me to spot you, when you're not a bit horsey-looking? Und. (with elaborate irony). Accept my compliments on a power of penetration which is simply phenomenal! Phill. (giving him a little push). Oh, go along—it's all talk with you—I don't believe you mean a word you say! Und. (to himself). She's becoming absolutely vulgar. (Aloud.) I don't —I don't; it's a manner I have; you mustn't attach any importance to it —none whatever! Phill. What! Not to all those high-flown compliments? Do you mean to tell me you're only a gay deceiver, then? Und. (in horror). Not a deceiver, no; and decidedly not gay. I mean I did mean the compliments, of course. (To himself.) I mustn't let her suspect anything, or she'll get talking about it; it would be too horrible if this were to get round to Lady Maisie or the Culverins—so undignified; and it would ruin all my prestige! Ive only to go on playing a part for a few minutes, and—maid or not—she's a most engaging girl! [He goes on playing the part, with the unexpected result of sending Miss Phillipson into fits of uncontrollable laughter. Scene XI.—The Back Entrance at Wyvern. The Fly has just set down Phillipson and Undershell. Tredwell (receiving Phillipson). Lady Maisie's maid, I presume? I'm the butler here—Mr. Tredwell. Your ladies arrived some time back. I'll
- 59. take you to the housekeeper, who'll show you their rooms, and where yours is, and I hope you'll find everything comfortable. (In an undertone, indicating Undershell, who is awaiting recognition in the doorway.) Do you happen to know who it is with you? Phillipson (in a whisper). I can't quite make him out he's so flighty in his talk. But he says he belongs to some Mews or other. Tred. Oh, then I know who he is. We expect him right enough. He's a partner in a crack firm of Vets. We've sent for him special. I'd better see to him, if you don't mind finding your own way to the Housekeeper's Room, second door to the left, down that corridor. (Phillipson departs.) Good morning to you, Mr.—ah—Mr.——? Undershell (coming forward). Mr. Undershell. Lady Culverin expects me, I believe. Tred. Quite correct, Mr. Undershell, Sir. She do. Leastwise, I shouldn't say myself she'd require to see you—well, not before to- morrow morning—but you won't mind that, I daresay. Und. (choking). Not mind that! Take me to her at once! Tred. Couldn't take it on myself, Sir, really. There's no particular 'urry. I'll let her ladyship know you're 'ere; and if she wants you, she'll send for you; but, with a party staying in the 'ouse, and others dining with us to-night, it ain't likely as she'll have time for you till to-morrow. Und. Oh then, whenever her ladyship should find leisure to recollect my existence, will you have the goodness to inform her that I have taken the liberty of returning to town by the next train? Tred. Lor! Mr. Undershell, you aren't so pressed as all that, are you? I know my lady wouldn't like you to go without seeing you personally; no more wouldn't Sir Rupert. And I understood you was coming down for the Sunday! Und. (furious). So did I—but not to be treated like this!
- 60. Tred. (soothingly). Why, you know what ladies are. And you couldn't see Deerfoot—not properly, to-night, either. Und. I have seen enough of this place already. I intend to go back by the next train, I tell you. Tred. But there ain't any next train up to-night—being a loop line— not to mention that I've sent the fly away, and they can't spare no one at the stables to drive you in. Come Sir, make the best of it. I've had my horders to see that you're made comfortable, and Mrs. Pomfret and me will expect the pleasure of your company at supper in the 'ousekeeper's room, 9.30 sharp. I'll send the Steward's Room Boy to show you to your room. [He goes, leaving Undershell speechless. Und. (almost foaming). The insolence of these cursed aristocrats! Lady Culverin will see me when she has time, forsooth! I am to be entertained in the servants' hall! This is how our upper classes honour poetry! I won't stay a single hour under their infernal roof. I'll walk. But where to? And how about my luggage? [Phillipson returns. Phill. Mr. Tredwell says you want to go already! It can't be true! Without even waiting for supper? Und. (gloomily). Why should I wait for supper in this house? Phill. Well, I shall be there; I don't know if that's any inducement. [She looks down. Und. (to himself). She is a singularly bewitching creature; and I'm starving. Why shouldn't I stay—if only to shame these Culverins? It will be an experience—a study in life. I can always go afterwards. I will stay. (Aloud.) You little know the sacrifice you ask of me, but enough; I give way. We shall meet—(with a gulp)—in the housekeeper's room! Phill. (highly amused). You are a comical little man. You'll be the death of me if you go on like that!
- 61. [She flits away. Und. (alone). I feel disposed to be the death of somebody! Oh, Lady Maisie Mull, to what a bathos have you lured your poet by your artless flattery—a banquet with your aunt's butler! Mamma (to Johnny, who has been given a Pear with Pills artfully concealed in it). "Well, dear, have you finished your Pear?" Johnny. "Yes, Mamma, all but the Seeds!"
- 62. A BETTING MAN ON CRICKET. Cricket may be a game, but I can't call it sport, For "the odds" at it aren't to be reckoned. There the last's often first ere you come into port, While the first is quite frequently second. There was Surrey, you see, slap a-top o' the tree, While Sussex was bang at the bottom. But, thanks to the in-and-out form of the three, You never know when you have got 'em! For when I backed Surrey with cheerful content. Why Kent walloped Surrey, and Sussex whopped Kent!!! OUR BOOKING-OFFICE. "There are, methinks," quoth the Baron, "two or three novels—one certainly I can call to mind—wherein the interior domestic life of Jews strict in the observance of their ancient and most touching religious rites and ceremonies is more amply, as well as more minutely, described than in Mr. Farjeon's Aaron the Jew, which, be it my pleasing duty to testify, is one of the best of this prolific author's works; a simple, touching story, the interest being well kept up, as of course the "interest" should be when dealing with the true history of one who commenced as a pawnbroker." As to the rites above mentioned, no special or intimate personal experience is shown to be possessed by the author, who could very easily have obtained his materials from an interesting work entitled, as I fancy, The Jew at Home, which has, the Baron regrets to say, disappeared from its shelf in the Baron's library. Aaron is lively, is gay, is witty, a "Jew d'esprit," and, like Mr. Peter
- 63. Magnus, he amuses a small circle of intimate friends; but his story, and that of his sweet wife Rachel, as related by Mr. Farjeon, will increase this friendly circle to a very considerable extent. The Baron ventures to think that a good deal of the dialogue and of the descriptive writing is unnecessary,—but Mr. Farjeon likes to give everyone plenty for their money,—and, further, that the story would have gained by the loss of what would have reduced the three volumes to two. But altogether, the novel is "recommended" by the interested but disinterested Baron de Book-Worms. A VOTE OF THANKS. By a Hard-up Journalist. [A strange light has appeared on that part of the surface of Mars not illuminated by the sun. The Westminster Gazette of August 2 asks the question, "Is Mars signalling to us?"] Oh, men of Mars, we thank you, your behaviour's really kind! (Forgive us if you've lately slipped somewhat out of mind!) For now the silly season's set in with all its "rot," You once more raise the question whether you exist or not. No doubt the good old topics will trot out yet again:— "Is Flirting on the Increase?" "Is Marriage on the Wane?" Big gooseberries as usual with sea-serpents will compete, To help the British Press-man his columns to complete!
- 64. But you, my merry Martians, have opportunely planned A mild but new sensation for the holidays at hand; Your planet's "terminator," it seems, is now ablaze— 'Tis, say the cognoscenti, a signal that you raise! What is it that you're shewing terrestrial telescopes? Is't pills you're advertising, or booming patent soaps? How on earth can one discover what by this beacon's meant, Whether news of Royal Weddings or Railway Strikes is sent? Alas! We haven't mastered the transplanetic code; Your canals are yet a riddle, in vain your fires have glowed! Still, do not let your efforts each August-tide abate— You furnish us with "copy," which maintains the Fourth Estate! Distinguished Visitors to Bournemouth.—The Royal Bath Hotel announces "Private Suites." Is "General Bitters" there also? Educational Motto. (For Mr. Acland's use.)—"A place for every child, and every child in its place."
- 65. ON A CERTAIN CONDESCENSION IN FOREIGNERS. He. "Oh, you're from America, are you? People often say to me, 'Don't you dislike Americans?' But I always say 'I believe there are some very nice ones among them.'" She. "Ah, I dare say there may be Two or Three nice People amongst Sixty Millions!" "MOWING THEM DOWN!" ["He (Sir William Harcourt) confessed that he was not enamoured of these
- 66. exceptional measures, and he resorted to them with extreme regret. But if he were asked for a justification of this motion, he would refer hon. gentlemen to the Order Book of the House of Commons."] Gunner Harcourt, loquitur:— Exceptional measures I hate, I'd rather not always be battling; The good old "Brown Bess" I prefer, I confess, To a new (Parliamentary) Gatling. To fight in the old-fashioned way, Good temperedly, fairly, politely, Is more to my mind; but these fellows, I find, Will not let a leader be knightly. If Balfour would only fight fair; And impose that condition on Bartley; If Joe would not ravage and shriek like a savage; Did Tommy talk less, and less tartly; Were Goschen less eager for scalps, And kept a tight rein upon Hanbury; Why then 'twere all right; we'd soon get through our fight And hatred in love's flowing can bury. But no, they're like Soudanese blacks, All fury and wild ugly rushes. They shriek and they shock, and they hack and they hock, Till chivalry shudders and blushes. And so the machine-gun, I find, Is just the one thing will arrest 'em. They've quite lost their head, but a fair rain of lead Played on them will try 'em and test 'em! Whir-r-r-r! George! how it's mowing them down, Their Advance-guard,—"Amendments" they dub them!
- 67. They swarm thick and thicker. The handle turns quicker! 'Tis dreadful; but then we must drub them. As Courtney so gallantly said, 'Tis "deplorable"; troubles me sorely. But if Arthur and Joe won't make terms, why, you know, They really can't blame me and Morley! AIRS RESUMPTIVE. II.—The Links of Love. My heart is like a driver-club, That heaves the pellet hard and straight, That carries every let and rub. The whole performance really great; My heart is like a bulger-head, That whiffles on the wily tee,— Because my love distinctly said She'd halve the round of life with me. My heart is also like a cleek, Resembling most the mashie sort, That spanks the object, so to speak, Across the sandy bar to port; And hers is like a putting green, The haven where I boast to be, For she assures me she is keen To halve the round of life with me. Some wear their hearts upon their sleeve, And others lose 'em on the links; (This play of words is, by your leave,
- 68. Rather original, one thinks;) Therefore my heart is like to some Lost ball that nestles on the lea, Because my love has kindly come To halve the round of life with me. Raise me a bunker, if you can, That beetles o'er a deadly ditch, Where any but the bogey-man Is practically bound to pitch; Plant me beneath a hedge of thorn, Or up a figurative tree, What matter, when my love has sworn To halve the round of life with me? THE YELLOW AGE. The poets sing of a Golden Age. Are we trying to start its fellow? The Yellow Aster is all the rage; The Yellow Races in war engage; The Primrose League wild war doth wage, And the much-boomed Book in cover and page Like the Age itself is—Yellow. Well, Yellow's the tint of Gold—and Brass! Of the Golden Calf—and the Golden Ass! Of the "livery" face and the faded leaf, But 'tis tedious, very, beyond belief. I own I am little inclined to smile On the colour of age, decay, and bile And mustard, and Othello; I'm tired, I own, of it's very look,
- 69. And I feel compelled to cock a snook At the Yellow Primrose, the Yellow Book. Though an Age indeed That runs to seed Is like to run to Yellow! "MOWING THEM DOWN!" Gunner H—rc—rt. "NOT MANY OF 'EM LEFT NOW!"
- 70. EARLY LOGIC. Little Girl (of inquiring mind, to Stud Groom, looking at a Mare in field with Foal). "How old is that little Horse?" Stud Groom. "Well, Missy, he's only Five Days old." Little Girl (to her Governess). "Oh, Nana, did I run about the Fields when I was Five Days old?"
- 71. A LITTLE HOLIDAY. Sunday.—How exhausting is London life! Up late, night and morning. Club. See summer number of illustrated paper. Pictures of pretty girls, reclining in punts, hammocks, or deck-chairs, doing nothing, men helping them. True holiday for jaded Londoner. Perhaps better without pretty girls. Even more reposeful. Must get right away. Secluded place. No pretty girls. That tiny inn Jones told me about. Miles from everywhere. Monday.—At Tiny Inn. Fine afternoon. Feel quite happy. With summer clothes, summer numbers, flannels, straw hat, and other suitable things. Seven miles from station. Beautifully clean. Perfectly quiet. Weather changing. Raining. Landlord says, "Soon over." Eggs and bacon for supper. To bed early. Tuesday.—Wake at five. Up at six to enjoy morning air. Eggs and bacon for breakfast. Still raining. Landlord says, "Very remarkable, since in this place it never rains." Somehow the clouds always pass over neighbouring village, following the course of the river, the ridge of the hills, or something. Have noticed in all country places that the clouds always do this, except when I am there. Impossible to lounge under a tree in this rain. Stop indoors, smoke, and read summer numbers. Eggs and bacon for lunch. Rain going on steadily. Put on flannels, go out. Drenched. Eggs and bacon for dinner. Landlord says they hope to give me some meat to-morrow. Butcher calls once a week apparently. Wet evening. Somewhat tired of sitting on horsehair sofa with damaged springs. Know all the summer numbers by heart. To bed at ten. Wednesday.—Wake at four. Toss about till six. Then up. Still raining. Breakfast,—eggs and bacon. Landlord says if I cross two fields I shall find the river and a punt. Thanks. Will wait till rain stops. He says it is
- 72. sure to stop soon. Ask him if one can get a London paper. Says they sometimes have one at the stationer's, four miles off, but generally only when ordered. Lends me a local paper of last week. Reduced to summer numbers again. Begin to wish there were some pretty girls here, after all. They might enliven things. After lunch,—of eggs and bacon,—resolve to go out. Ask landlord where one can go. Don't like to ask "if any girls about anywhere?" Accidentally landlord does happen to mention Farmer Muggeridge's daughters. I pretend indifference, but inquire as to direction of Muggeridge's farm. Lose my way. Wander helplessly. Steady downpour. Return, drenched. Butcher has not been. Eggs and bacon for dinner. Smoke, and read advertisements—plenty of them—in summer numbers. To bed at nine. Thursday.—Wake at three. Toss about till seven. Then breakfast— usual dish. Rain, not quite so heavy. With fuller directions as to road, start hopefully for Muggeridge's farm. Arrive there. Heavy rain again. Muggeridge loafing about. Country people always loaf about in rain. They seem to enjoy it. Chat with him. He asks me in to have some cider. Accept. Chance of seeing charming daughters. They enter! Now!... Oh! awful!... Cider acid. Obliged to drink it. Hurry back. Lunch. Usual dish. Still raining. Call in landlord, and ask eagerly about trains to London. The next is to-morrow morning, at 8.20. Give way to despair. Refuse eggs and bacon for dinner. Bed eight. Friday.—Leave in landlord's cart at seven, after usual breakfast. Still raining steadily. Gave landlord all those summer numbers to amuse future weather-bound visitors with imaginary pictures of rural happiness. London once more! Hurrah! Dinner—not eggs and bacon. Theatre. Smoke at club. Avoid Jones. Tell Smith I know the sweetest place for country peace and seclusion. He writes down the address eagerly. Those summer numbers will amuse him. To bed—any time!
- 73. At the Window.—Judging from the tone of James Payn's delightful Note-Book this week, one fears that charming and cheery gossiper has been "laid up," has been compelled to take his "Notes" from a sick- couch at a window—has, in fact, for the time, become a window-Payn! Well, a window is no bad coign of vantage for an observant penman. "The World from a Window" would make an excellent book, and James Payn would be the very man to write it. Let Mr. Payn think of it. Mr. Punch's present purpose, however, is to wish his good friend and favourite writer speedy emancipation from the bonds of sickness and compulsory window-watching.
- 74. PREHISTORIC PEEPS. The Naval Manœuvres afforded much pleasurable Excitement to those concerned! SATURDAY POPS. NEW SERIES. "Rusticus," who is clearly "Rusticus Expectans," wasmoved to write to the Chronicle on July 31st, to say that,though not a rich man, he lives in a pretty Surrey village within an eightpenny return railway fare of the City; and has a fairly large and quiet garden, with field, &c. "The trees are all at their finest," he proceeds, "the flowers looking very gay and walking in the garden." Capital fun this, when flowers actually walk about. But no! it's "walking in the garden to-day the thought came to me," so it's a walking thought, comparable, doubtless, to a running commentary. Anyhow. "Rusticus" is moved—by the thought of a "tired working-man or band of City workers" who would find in his garden pleasure on a quiet Saturday afternoon—to make an offer. Here are his words:— "I am a bachelor, therefore I say, men, you are welcome to my very simple hospitality if it is of any use to you. I can do with a limited number every or any Saturday. Any creed or class is welcome. All I stipulate for is honest souls. Come and smoke and talk under the trees and spend a quiet time away from the town. I simply condition —no publicity or fuss, the giving and acceptance of the invitation quietly, honestly, brother to brother. Would you, Sir, forward any letters on to me?" This is of course an example which will be followed, and Mr. Punch has already had the following letter (amongst others), which he now
- 75. prints with pleasure. Sir,—Owing to the Death Duties, I am no longer a rich man, but I have a little house in Piccadilly, not more than a twopenny 'bus ride from Charing Cross. It has occurred to me that some hungry working- man might like to drop in to a quiet little dinner some night. I am a Duke, therefore I say, comrades in depression, you are welcome to my roof, if it's of any use to you. I can dine a hundred or so of you any or every night. All I stipulate for is that there shall be no speaking, for speaking bores me horribly. D-v-nsh-re. A TOWN MOUSE.
- 76. Jones. "Well, my little Man, what are you thinking about?" London Boy (who has never been out of Whitechapel before). "I'm thinkin' it's time yer Mother put yer into Trousers!" LOWERED! Rates, rates, rates, Of an exigent L. C. C.! And I'm glad they can't hear the language We utter so frequentlee! O well for the excellent Chairman For trying to reduce them a bit! O well for those Councillors wary Who on costly "improvements" sit! And "demand-notes" still go on, And our pockets are steadily bled; But "O (we oft sigh) for a tenpenny rate, And the sins of a 'Board' that is dead!" Rates, rates, rates! Thanks, men of the L. C. C.! We trust the farthing now taken off Will never go back to ye!
- 77. "AFTER THE HEALTH CONGRESS IS OVER." Scene—A Ball Room at the Mansion House. He. (resting). Good floor, isn't it? She. Quite. But tell me, have you been attending the Congress? He. Of course; that is why I received an invitation to-night. She. And you found the lectures and all that most interesting? He. Yes, very; and then there were the Opera and the theatres in the evening. She. But do let us talk about the Congress. Did you not discuss sanitation? He. Discussed it very much indeed. So fortunate too that we had the meeting before everybody had left town. She. Yes. But did you not inquire into microbes and all that? He. Certainly; had a lot of talk about them, and finished them all up just in time not to interfere with Goodwood. She. And I suppose you found out the way to keep everyone in perfect health? He. That was the idea, and yet we floored Lords and the Oval. She. But oughtn't every town to be in a satisfactory condition? He. Why, yes. But that depends upon the season of the year. Of course, some places are deadly dull when nothing's going on from a social point of view. She. I mean from a health point of view—oughtn't everything nowadays to be simply excellent?
- 78. He. Yes, of course. That's the modern theory. She. And yet, according to the papers, London is full of fever and insanity. He. I daresay; the Press men generally get their figures right. She. But if, theoretically, everything is right, why should most things be practically wrong? He. You must really ask me another. She. But you are strong upon health, are you not? He. Very—in the lecture-room. And now, if you are rested, we will have another turn. [Exeunt dancing. ESSENCE OF PARLIAMENT. EXTRACTED FROM THE DIARY OF TOBY, M.P. House of Commons, Monday, July 30.—Having settled Budget Bill, and, incidentally, brought Chancellor of Exchequer to Death's Door by observations on Death Duties, Tommy Bowles has time to turn his attention to another social question. Looks as if he were going to take the Bicycle Fiend by the scruff of the neck. Herein he has opportunity of deepening and enlarging his hold on affection and esteem of British public. Bicycle Fiend has increased, is increasing, and, at least, ought to be registered. He comes upon the hapless rider or pedestrian in quiet country lanes, brushing him aside as if the earth were the Fiend's and all the highways thereof. Bad enough in the country, where there is room to get out of the way. In crowded streets of metropolis, Fiend
- 79. pounces round unsuspected corners upon elderly gentlemen, scattering streams of peaceful passengers at peremptory sound of fearsome bell. Tommy B. got his eye on him. Not without suspicion that this new departure has something to do with old, now closed, campaign against the Budget. Tommy warned the Squire whilst in Committee that his Death Duties would not reap the full harvest anticipated. Every little helps. What with actual concussions and sudden frights, Bicycle Fiend leads in course of financial year to considerable succession of property changing on sudden death, with concurrent toll paid to Treasury. If the Bicycle Fiend can only be placed on same footing as the common carrier, or the harried hansom-cab driver, the death-rate would appreciably decrease, and with it the flow of legacy and succession duties. Tommy may or may not look thus far ahead. No matter, if he only succeeds in restraining a nuisance that is a disgrace to a civilised community. The Member for Sark tells me he has a Short Way with the B. F., which makes him to considerable extent indifferent to slower action of Home Secretary, who has evidently never had his shins barked by this agency. Sark says when he takes his walks abroad he usually carries a stick or umbrella. When, crossing a road, he hears the tinkle of the Fiend's bell, insolently and imperatively ordering him out of the way on pain of being run over, he, instead of flying for his life, as is the use of the ordinary citizen, carelessly throws stick or umbrella lance-wise across hollow of right or left arm, according as the Fiend approaches from one direction or the other. Thus armed he leisurely pursues his way. If the Fiend continues on the track, he will run with face or chest on to the point of the umbrella. As that would be inconvenient to him, he slows up or goes on another tack, and when he arrives home writes a letter to the Bicycling Blister, indignantly denouncing a street passenger who wouldn't get out of his way. Business done.—Vote on Account through Committee. Tuesday.—"Prince Arthur," said Sark, looking across at the Front Opposition Bench whilst Courtney was speaking, "succeeds in hiding all traces of storm behind a smiling countenance. Joseph, on the contrary,
- 80. more ingenuous, less acute in practice of worldly wiles, enables one to realise, even at this long distance of time, what Balak, the son of Zippor, King of Moab, looked like when he stood in the high places of Baal, and listened to Balaam's remarks on the motion for the time-closure to be applied to the Children of Israel, who had pitched their tents in the plains of Moab beyond the Jordan at Jericho, and declined to budge at the bidding of Balak." Appearance of Parliamentary Balaam on scene dramatically effective. Crowded House worked up to highest pitch of excitement by swift encounter, in which John Morley had followed Prince Arthur, and Joseph, springing in from behind, had clouted the Chief Secretary on the head. The Squire had moved time-closure on Evicted Tenants Bill in speech the studied tameness and provoking brevity of which had riled Opposition much more than if he had belaboured them with Harcourtian phrase. Sage of Queen Anne's Gate said a few words, preparatory to packing up for holiday; then Courtney rose from Joseph's side to continue debate. Members, taking it for granted that he, possibly with some reservations in favour of Eviction Bill whose second reading he had supported, was about to say ditto to Joseph on question of Closure, began to move towards door. Arrested by Courtney's solemn tone, and his expression of regret, evidently unfeigned, at deplorable condition in which the House found itself. "Woe to those through whom offences come!" cried Courtney in voice which, as he said, was of one crying in the wilderness, and seemed for its perfect effect to lack only hirsute garb, stave and honeypot. "Through whom did the offence come? Surely," continued the Prophet, bending shaggy eyebrows upon the bench where the Busy B's hive, "the offence lies with those Members who, disregarding the true uses, functions, duties, and high mission of the House, abuse their powers, intent to destroy possibility of the right conduct of public business." Not Ministers, then, with the Squire at their head, responsible for the deadlock, as Prince Arthur had painted the scene, and as Joseph had touched it up with stronger colour. It was the Busy Bees. They and "a junta of irresponsible landlords enforcing their will upon those who ought to resist them."
- 81. O Balaam! Balaam! M.P. for Bodmin. Was it for this Joseph led thee into the field of Zophim, to the top of Pisgah? For this did Prince Arthur build seven altars, and offer up the Squire of Malwood on every one of them? Long time since such a scene was wrought in the House. Saunderson pished and pshawed, and looked anxiously round for Logan. Bartley blushed; Hanbury was hushed; and a tear trickled down the pale cheek of Tommy Bowles—Cap'en no longer, disrated and denounced. Business done.—Time-Closure resolution carried. Thursday.—Such larks! Yesterday time-closure came into operation in connection with Evicted Tenants Bill. Arranged that if debate on Clause I not finished by eleven o'clock to-night, all Amendments remaining on paper shall be submitted to vote without further debate. Obstruction scotched; wriggles helplessly, like eel in muddy depths of river, smitten by the spear. "Shan't play," whimper Prince Arthur and Joseph, mingling their tears at this fresh evidence of tyranny, this last illustration of man's inhumanity to man. Strike ordered in Unionist lines. Men throw down the pick; hand in the shovel and the hoe; put on their coats; hang about corners of Lobby in approved strike fashion. If Hanbury and the Blameless Bartley could only be induced to stick short clay pipe in side of mouth (bowl downwards), fasten a leather strap outside their trousers just below the knee, and drink four-half out of pewters at bar in the Lobby, scene would be complete. Strike only partial. Fully one half the men refuse to go out; stand by the masters, turning deaf ear to blandishments and threats of pickets outside. Strange thing is that, working at half strength, output more than doubled. Time-closure, with all hands at work, proposed to complete Committee by eleven o'clock next Tuesday night. At ten minutes past six this afternoon the whole thing through. Not hurried either. Thoroughly debated, divided on, and Bill, in more than one instance, amended.
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