Comparison of magnetic and dielectric properties of transition metal nanospinel ferrites, MFe2O4, (M = Co, Cu, Ni, Zn) synthesized by one-pot combustion route

Abstract

Transition metal spinel ferrites of the formula MFe2O4, (M = Co, Cu, Zn & Ni) were synthesized successfully by very simple one pot solution combustion method through glycine - nitrate route. Characterization was carried using techniques like Powder X ray diffraction (PXRD), Fourier transform Infra-red (FTIR) spectroscopy and Scanning electron microscopy (SEM), which reveals that these ferrites are in the nano crystalline size in the range of 20–60 nm. Also it displays that these spinel ferrites are in single phase and pure form. Vibrating sample magnetometer (VSM) measurements shows that all ferrites are magnetic in nature. CoFe2O4 was found to be a hard magnet whereas NiFe2O4, ZnFe2O4 and CuFe2O4 are soft magnets. To study and compare the dielectric characteristics we used impedance analyzer. Dielectric constant, loss tangent and ac conductivity was measured as a function of increasing frequency and the effect of calcination temperature was also analyzed for all the ferrites. The gradual decrease in dielectric constant and loss tangent with the rise in frequency shows that the ferrites can act as semiconductors. AC conductivity was found increasing with respect to frequency and calcination temperature of the sample. Calcination temperature effect was studied to understand the variation of different conductivity properties which gave an understanding of processing temperature.