Study of Structural and Magnetic Properties of In3+ Substituted Mg-Mn-Ni Spinel Ferrites

Effect of substitution of trivalent indium ions in stoichiometric magnesium-manganese-nickel ferrites has been studied with composition Mg0.2Mn0.5Ni0.3InxFe2-xO4 with x varying from 0.1 to 0.3 in steps of 0.1 using citrate precursor technique Single-phase cubic spinel structure of these samples has been confirmed from X-ray analyses. Ferrites have been investigated for their electric and magnetic properties such as dc resistivity, saturation magnetization, initial permeability and relative loss factor (RLF). DC electrical resistivity (rho) decreases with increase in temperature exhibiting semiconductor like behavior Bulk density increases and initial permeability (mu i) decrease with increasing In3+ substitution. But mu(i) increase with increasing sintering temperature for all composition. Fairly constant value of initial permeability over a wide frequency range (0.1-15 MHz) and low values of relative loss factor of order of 10(-6)-10(-5) are main achievements of present investigation. Saturation magnetization (Ms) and retentivity decreases while coercivity (Hc) increases with increasing substitution of indium ion.