Effect of Annealing Temperature on the Physical Properties of Zn-ferrite Nanoparticles
Thermally switched cationic exchange in magnetically ordered ZnFe2O4 (ZFO) nanoparticles synthesized via the coprecipitation route has been studied. The ZFO sample synthesized at 343 K and further annealed at 573 K is devoid of any X-ray diffraction (XRD) peak. However, the samples annealed at temperatures 673–973 K show clear XRD peaks indexed to a cubic spinel ferrite. The average crystallite sizes of the ZFO were calculated using Scherrer’s formula and found in the range of 10–16 nm. The lattice parameter of ZFO nanoparticles increased from 8.212 to 8.524 nm as the annealing temperature was raised from 673 to 973 K. Despite the fact that ZFO is antiferromagnetic in bulk, the ZFO nanoparticles annealed at temperatures ≥673 K show a magnetic hysteresis loop. The value of spontaneous magnetization has been decreased from 22 to 16 emu/gm with an increase in the annealing temperature. The electron spin resonance spectra show a single resonance peak with linewidth ranging from 147 to 243 Oe.
KeywordsFerrite Calcination Temperature Electron Spin Resonance Spectrum Average Crystallite Size ZnFe2O4
S.S. and N.K. thank the Department of Science &Technology, Government of India for funding this research through the project grant SR/FTP/PS-04/2008.
- 5.Thakur, S., Katyal, S.C., Gupta, A., Reddy, V.R., Singh, M.: J. Appl. Phys. 105, 07A521 (2009) Google Scholar
- 7.Jeong, J., Min, J.H., Song, A.Y., Lee, J.S., Ju, J.S., Wu, J.H., Kim, Y.K.: J. Appl. Phys. 109, 07B511 (2011) Google Scholar
- 11.Joint Committee on Powder Diffraction Standards (JCPDS) Card No. 82-1042 Google Scholar
- 12.Cullity, B.D.: Elements of X-ray Diffraction. Addison-Wesley, New York (1978) Google Scholar
- 14.Thomas, M., George, K.C.: Indian J. Pure Appl. Phys. 47, 81–86 (2009) Google Scholar