Structural characteristics and electrical properties of copper doped manganese ferrite

A series of Mn1-xCuxFe2O4 ferrite samples with 0.2 <= x <= 0.5 were prepared using the co-precipitation method. X-ray analysis confirmed the formation of single phase cubic spinel structure for all concentrations. Rietveld refinement revealed that the Mn1-xCuxFe2O4 with all concentrations of x belongs to normal spinel structure. The lattice parameters decrease leading to the increase in the X-ray density with increasing the copper concentration and this may be due to the difference in the ionic radii between Mn2+ and Cu2+. The decrease in the crystallite size with increasing the copper content is attributed to the higher formation temperature. The IR absorption spectra analyses were used for the detection and confirmation of the chemical bonds in spinel ferrites. The AC electrical conductivity, real part of the dielectric constant and the loss tangent tan delta were studied as a function of the applied frequency and temperature. It was found that the AC electrical conductivity increased with increasing temperature, this increase may be related to the increase in the drift mobility of the charge carriers, which are localized at ions or vacant sites. The AC conductivity increases with increasing copper concentration which may be ascribed to the decrease in hopping length. The dielectric constant epsilon' and dielectric loss showed a decrease with increasing frequency and increase with increasing temperature for all compositions. The dielectric behavior is explained by using the mechanism of polarization process. (c) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.