Effect of indium substitution on the electrical and magnetic properties of Ni–Zn ferrite

Indium-substituted polycrystalline nickel zinc ferrites of different compositions Ni0.65Zn0.35Fe2-xInxO4 (x = 0.00, 0.04, 0.08, 0.12, 0.16, 0.2) have been prepared by solid-state reaction route. Calcination and sintering of all samples were done in air atmosphere at 950 C and 1250 C, respectively, followed by natural cooling to room temperature. Characterization of the basic composition was done by X-ray diffractometry, saturation magnetization and Curie temperature. The effect of incorporation of larger indium ions in place of iron was studied with the help of saturation magnetization, Curie temperature, permeability, magnetic loss factor, DC electrical resistivity and dielectric properties. The highest magnetization and permeability values of the present system under study are 74.1 emu/g and 438 for the basic composition (concentration x = 0). The DC electrical resistivity was found to decrease up to x = 0.3 and increase thereafter. The variation in the electric and magnetic properties of this ferrite system is dominated by the decrease in iron concentration. Characteristic high dielectric constant values were recorded for these bulk ceramic materials.