Influence of Li substitution on structural and magnetic properties of Li_xNi_(0.2)Mg_(0.8-2x)Fe_(2+x)O_4

摘要

The structural and magnetic properties of polycrystalline Li_xNi_(0.2)Mg_(0.8-2x)Fe_(2+x)O_4 (where x=0.00, 0.10, 0.20,0.30 and 0.40) synthesized by the conventional solid state reaction method is reported. The X-ray diffraction patterns reveal that these compositions are single phase having spinel structure. Lattice constants of the compositions are found to decrease with increasing Li content. The bulk density and average grain diameter are observed to increase with increasing Li content for a fixed sintering temperature and also increase with increasing sintering temperature for a fixed chemical composition. As sintering temperature goes higher, porosity decreases and real part of the initial permeability increases. Increase of initial permeability is more than double (66) compared to parent composition (31). The saturation magnetization at room temperature is found to increase with increasing Li content due to the modification of cations distributions. The observed features of lattice constant, density, microstructure, initial permeability and DC magnetization of the investigated compositions are explained.