Synthesis, Structural and Magnetic Properties of Chromium Substituted Mn-Zn Ferrite

F. Alam, Bablu Chandra Das and A. K. M. Akther Hossain

Substitution of chromium in Mn-Zn ferrite and its effect on structural and magnetic properties has been studied. Samples were synthesized by combustion method and sintered at various temperatures (Ts). XRD patterns indicate that the samples are of single phase cubic spinel structure. The lattice parameter decreases with increase with substitution of Cr3+ content. Average grain size (D), bulk density (ρB), initial permeability (μi / ), Néel temperature (TN) decrease with the increase in chromium content. ρB was found to increase with increase in Cr3+ content as the Ts is increased. The Ts affect the densification, grain growth and μi / of the samples. μi / strongly depends on D, density and intragranular porosity. TN was found to decrease with the increase in Cr3+ concentration. This is attributed to the weakening of A-B interaction. The sharp fall of μi / at TN indicates that the compositions are homogeneous. Saturation magnetization (Ms), Coercive field (Hc), Residual induction (Br) were studied as a function of Cr3+ content. The Ms was found to decrease with the increase of Cr3+ content, which is attributed to the dilution of A-B interaction. The inclusion of Cr3+ caused the Ms, Br and hysteresis losses to decrease.