Synthesis and AC Electrical Characterization of Co Doped Bismuth Manganite Nanoparticles

Abstract

Multiferroic bismuth manganites (BiMnO3) possess both ferromagnetic and ferroelectric properties. Their electrical properties can be controlled by doping for useful applications. In this work single-phase cobalt doped bismuth manganite nanoparticles having general formula BiMn1-xCoxO3 (x=0, 0.2, 0.4, 0.6) were synthesized by co-precipitation method. Structural properties like lattice parameters and crystallite size of samples were determined by the data obtained by X-rays diffraction. The dielectric constant (ε) and dielectric loss tangent (tanδ) of samples were investigated as a function of frequency from 20Hz-3MHz using ac measurement data. For all the compositions dielectric constant was decreased with increasing frequency, however it increased with the increase in cobalt content. However cobalt addition causes a decrease in loss tangent as compared to pure BiMnO3 composition. The origin of this behavior is discussed in terms of Maxwell-Wagner and Koops model. Substitution of Mn with Co, in BiMnO3-based compounds is supposed to cause better properties in terms of tangent loss.