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This document summarizes a presentation given by Miss. Sarita Kumbhar on her research synthesizing and characterizing nickel-zinc ferrite thin films under the guidance of Prof. C. H. Bhosale. The presentation covered the methodology using spray pyrolysis, results from XRD, SEM, AC conductivity, and dielectric property measurements. Key findings included that the nickel-zinc ferrite thin films had a polycrystalline spinel cubic structure, smooth and uniform surface morphology, AC conductivity dependent on frequency, and decreasing dielectric constant with increasing frequency. Impedance spectroscopy also provided insight into grain boundary behavior.
![Types of spinel ferrite
1) Normal spinel ferrite: [M2+]A[Fe3+2]B O2-4
2) Inverse spinel ferrite: [Fe3+]A [M2+ Fe3+] BO2-4
3) Random spinel ferrite: [M2+x Fe3+1-x]A [M2+1-xFe3+1+x]B O2-4
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9](https://image.slidesharecdn.com/291sarita-131211235334-phpapp02/85/291-sarita-9-320.jpg)
291 sarita
- 1. A Presentation on Synthesis and characterization of spray deposited nickel-zinc ferrite thin films by Miss. Sarita Kumbhar under the guidance of Prof. (Dr). C. H. Bhosale Electrochemical Materials Laboratory, Department of Physics Shivaji University, Kolhapur 416004 December 2013 2 1
- 2. Outline of the presentation Introduction Methodology Results and Discussion 1) XRD 2) SEM 3) AC conductivity 4) Dielectric properties 5) Impedance spectroscopy Conclusions 2 2
- 3. Introduction In recent years, the magnetic materials have more demand in information and communication technology, because of their high frequency applications. Ni-Zn ferrite exhibits favorable properties such as high resistivity, low eddy current losses and high saturation magnetization. The trend for down sizing electronic equipment’s and the potential applications of ferrite materials have lead to the fabrication of ferrites thin films. 3 3
- 4. The bulk component of ferrites can not be compatible with rapid development of electronic applications. But, the thin films of ferrite are used in microwave integrated circuits (MIC), and essential for the miniaturization of magnetic products. 4
- 5. Ferrite Ferrites are the most important magnetic materials, without which we can not think about technological revolution. These are very well established group of magnetic materials of the transition metal oxides. Ferrites are mixed metal oxides with iron oxide as their main component having general formula MFe2O4. 4 5
- 6. Classification of ferrites Soft Ferrite: Ferrites with low coercive force are called soft ferrites. eg. Nickel-zinc ferrite, Manganese-zinc ferrite etc. Hard Ferrite: Ferrites with high coercive force are called hard ferrite. eg. Barrium ferrite , Stonsium ferrite etc. 6
- 7. Spinel Ferrite The spinel structure is derived from the mineral spinel, which was first determined by Bragg in 1915. Spinel ferrites are very stable due to their stable crystal structure, and they are predominantly ionic. 7
- 8. Crystal structure of Spinel Ferrite Tetrahedral site - A Site ions - B Site ions - Oxygen ions Octahedral site 64 tetrahedral sites – only 8 surrounded by divalent metal ions (A-Site) 6 32 octahedral sites – only 16 surrounded trivalent metal ions (B-Site) 8
- 9. Types of spinel ferrite 1) Normal spinel ferrite: [M2+]A[Fe3+2]B O2-4 2) Inverse spinel ferrite: [Fe3+]A [M2+ Fe3+] BO2-4 3) Random spinel ferrite: [M2+x Fe3+1-x]A [M2+1-xFe3+1+x]B O2-4 7 9
- 10. Methodology 10
- 11. Spray syrolysis set up Spray pyrolysis is simple and expensive chemical deposition method for producing thin films on large area Schematics of spray pyrolysis showing its various parts 11
- 12. Expremental Conditions 1 Precursors Nickel nitrate, Zinc Nitrate, Ferric nitrate 2 Solvent Water 3 Quantity 30 ml 4 Deposition temperature 400 0C 5 Concentration 0.1 M 6 Spray rate 2 cc/min 12
- 14. X-ray diffraction patterns for NixZn1-xFe2O4thin films from x = 0.5 to x = 1.0 14
- 15. 0.5 0.6 0.7 0.8 0.9 1.0 Scanning electron micrographs of NixZn1-xFe2O4thin films, from x = 0.5 to x = 1.0 15
- 16. Variation of AC conductivity with frequency at room temperature for NixZn1-xFe2O4 thin films 16
- 17. Variation of dielectric constant with frequency at room temperature for NixZn1xFe2O4 thin films 17
- 18. Complex impedance spectra forNixZn1-xFe2O4thin films from x=0.5 to x=1.0 18
- 19. Conclusions Preparation of NixZn1-xFe2O4 thin films by using spray pyrolysis technique is possible. The X-ray diffraction (XRD) analysis reveals that the NixZn1-xFe2O4 thin films are polycrystalline with spinel cubic structure. The SEM images show the surface of the film is smooth and having uniform nature. The conduction mechanism can be understood from the AC conductivity studies. 19
- 20. The dielectric constant decreases with increase in frequency. The grain boundary behaviour can be studied from the impedance spectroscopy. 20
- 21. THANK YOU