Chemical Synthesis and Magnetic Properties of Indium-Substituted Manganese-Zinc Nanoferrites

Nanocrystalline ferrites with composition Mn_0.2Zn_0.8In_yFe_2-yO₄, (y = 0.00, 0.035, 0.070, 0.100) were prepared by oxalate co-precipitation technique followed by microwave heating of precursors. The phase purity of the samples was confirmed by X-ray diffraction technique. Full profile Rietveld refinement of the powder diffraction pattern was carried out by using General Structure Analysis System II to obtain cation distribution in the spinel lattice. In³⁺ ions were distributed in tetrahedral as well as octahedral sites. Magnetization of ferrite samples was studied with vibrating sample magnetometer. In lower concentration, indium substitution increased saturation magnetization; at higher concentration of indium, saturation magnetization decreased substantially. This was due to higher fraction of indium ions occupying octahedral sites. AC susceptibility and Loria-Sinha techniques were used to study Curie temperature of nanoferrites.