AC conductivity and dielectric properties of, Zn1-xCuxCr0.8Fe1.2O4 spinel ferrites

The ac conductivity and dielectric properties of spinel ferrite samples - having the chemical compositions Zn1-xCuxCr0.8Fe1.2O4 (0 <= x <= 1) - were investigated as function of frequency and temperature by using a complex impedance technique. The ac conductivity shows semiconducting behavior and almost constant values over a wide range of frequency at different temperatures. This stability besides its very low values around room temperature indicates that the studied compositions may be good candidates for many applications. The peaks of the dielectric constant occurring at some elevated temperatures can be attributed to a collective contribution to the polarization by two types of charge carriers while the peaks of the dielectric loss tangent are attributed to the coincidence of the hopping frequency of charge carriers with the frequency of the applied field. (c) 2009 Elsevier B.V. All rights reserved.