Influence of Zn Substitution on Structural, Magnetic and Electrical Properties of MgFe2O4

Polycrystalline spinel ferrites ZnxMg1-xFe2O4 (where x = 0.0, 0.1, 0.15, 0.2, 0.25 and 0.3) were prepared by standard ceramic method and characterized by x-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer. Structural, electric and magnetic properties have been discussed in detail on the basis of Zn composition. The composition shows formation of a single-phase cubic spinel structure and the lattice constant 'a' increases with increasing Zn concentration. FTIR spectra show two prominent frequency bands in the wave number range 400-600 cm(-1), which further confirms the cubic spinel structure and completion of chemical reaction. Magnetic studies revealed that the saturation magnetization increases with increasing the substitution of Zn. Cation distribution for the present system was estimated by comparing observed and calculated x-ray line intensities. From this it is observed that Zn2+ ions prefer to occupy A sites, and Mg2+ and Fe3+ ions distributed into both A and B sites. The observed variation in magnetization has been explained on the basis of distribution of cations among A and B sites of the spinel lattice. A significant influence of cation distribution is observed on DC electrical resistivity and activation energy.