Influence of In₂O₃ Addition On The Magnetic And Electrical Properties of Iron – Deficient Ni-Zn Ferrite

Abstract

The influence of low melting In₂O₃ addition on the magnetic and electrical properties of irondeficient  ferrites of composition. Ni_0.65Zn_0.35Fe_1.96O₄ + xIn₂O₃(x = 0, 0.005, 0.01, 0.015, 0.02,  0.025, 0.03 and 0.035) was investigated. Single phase spinel structure of all sintered samples were  confirmed by X-ray diffraction. The lattice parameter of the samples increased with the increment  of In₂O₃. The effect of In₂O₃ (melting point 680°C) can be explained by the formation of liquid  phase on the grain surface due to reaction of In₂O₃ with the spinel phase at 1250°C sintering  temperature. Saturation magnetization decreased almost linearly and Curie temperature linearly  with the increasing addition of In₂O₃. The decrease in magnetization was possibly due to diamagnetic In³⁺ ions occupy B-sublattice ( octahedral sites) and replace Fe³⁺ ions keeping the  magnetization of A-sublattice (tetrahedral sites) unchanged. When indium ions occupy B-sites and  replace Fe³⁺ ions, the magnetization of B-sublattice (M_B) decreases keeping the magnetization of  A-sublattice (M_A) constant which in turn weakens A-B exchange interaction (M = M_B-M_A). The dc  resistivity of the samples increased almost linearly with the addition of In₂O₃. With the increasing  addition of In₂O₃, In³⁺ ions occupy B-sites which reduces Fe²⁺ to Fe³⁺ electron hoping conduction  in octahedral sites and contributes to increase in resistivity.

DOI: http://dx.doi.org/10.3329/jbas.v36i2.12957

Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 153-158, 2012