Temperature Dependent Dielectric Behaviour of Nanocrystalline Co_0.5Mg_0.5Cr_0.4Fe_1.6O₄ Ferrite

Abstract

Chromium substituted Co‐Mg ferrite with composition Co0.5Mg0.5Cr0.4Fe1.6O4 has been synthesized by solgel auto combustion method. X‐ray diffraction technique confirmed the formation of cubic spinel structure with no additional phase. In order to distinguish the effect of crystallite size‐ induced broadening and strain‐ induced broadening of XRD peaks, Williamson and Hall analysis has been performed. Dielectric constant, dielectric loss tangent and ac conductivity have been measured in the frequency range 50 kHz–120 MHz at room temperature. The decrease in dielectric constant with increasing frequency is attributed to Maxwell Wagner model. The variation of dielectric constant and loss tangent with temperature at different frequencies have also been studied.