Structure and electrical properties of Co0.5CdxFe2.5-xO4 ferrites

We have studied the Cd ion doping effects in cobalt ferrite using X-ray diffraction (XRD), dielectric and impendence spectroscopy at room temperature. X-ray diffraction analysis indicates that all the samples exhibit a single phase nature with cubic spinel structure. The dielectric constant epsilon', epsilon '', loss tangent tan delta and sigma(ac) have been studied as a function of frequency and composition. It is observed that doping of the Cd ions increases epsilon', epsilon '', tan delta and sigma(ac) up to 20% after that it start decreasing with further doping. The dielectric properties and ac conductivity in Studied samples have been explained on the basis of space charge polarization according to Maxwell and Wagner's two-layer model and the hoping between adjacent Fe2+ and Fe3+ as well as the hole hopping between Co3+ and Co2+ ions at B-sites. The complex impedance analysis used to separate the grain and grain boundary of the system Co0.5CdxFe2.5-xO4. (C) 2007 Elsevier B.V. All rights reserved.