Influence of chromium substitution on structural, electrical, and magnetic properties of Ni-Zn-Cu ferrites

Abstract

In this work, Ni0.5Zn 0.3Cu0.2Fe2-xCrxO4(x = 0:02, 0.04, 0.06, 0.08, and 0.1) ferrites are synthesized by sol-gel method, and study how relevant properties of the samples are modified accordingly. The structural, morphological, magnetic, and electrical features of the ferrites are evaluated by X-ray diffraction, scanning electron microscope, the Fourier transmission infrared spectra, vibrating sample magnetometer, electron spin resonance, and network analyser. The lattice constant decreases with chromium concentration and the decrease in lattice constant is attributed to the smaller ionic radius of chromium compared to iron. Distribution of metal cations in the spinel structure, estimated from X-ray diffraction data, show that along with Ni2+ions, most of the Zn2+and Cu2+ions additionally occupy the octahedral B sites. The Fourier transform infrared spectra revealed two prominent frequency bands in the wave number range 400-600 cm-1which confirm the cubic spinel structure. Magnetic properties, such as initial permeability, saturation magnetization, and coercivity have been investigated at room temperature. The frequency dependent dielectric constant is observed to decrease with the increased chromium concentration. This behaviour has been explained in accordance with the Koops phenomenological theory.