Valence compensated perovskite oxide system Ca1-xLaxTi1-xCrxO3. Part III: Impedance spectroscopy

Abstract

Electrical behaviour of the compositions with x ≤ 0.50 in the Ca1-xLaxTi1-xCrxO3 system has been studied by employing complex plane impedance and spectroscopic analysis in the temperature range 100 K-550 K. These studies have revealed the contribution of three processes to the total electrical conductivity of these samples. An equivalent electrical circuit model, which contains series arrangement of three paralle RC elements, is proposed to represent the electrical characteristics of these materials. Out of these three, two processes correspond to the activated hopping processes within the bulk while the third process corresponds to the barrier layer formation in these ceramics. Immittance spectroscopic analysis shows that conduction occurs through localized as well as long range movement of charge carriers. © 2001 Kluwer Academic Publishers.