Valence compensated perovskite oxide system Ca1−xLaxTi1−xCrxO3 Part I Structure and dielectric behaviour

Abstract

Attempts have been made to synthesize compositions with x = 0.01, 0.03, 0.05, 0.10, 0.20, 0.30 and 0.50 in the valence compensated system Ca1−xLaxTi1−xCrxO3by solid state ceramic method. Solid solutions form upto x≤ 0.50. All the compositions have been found to have orthorhombic structure. The structure of the compositions upto x≤ 0.10 is similar to that of CaTiO3. The structure changes gradually from CaTiO3to LaCrO3in the composition range 0.10 < x < 0.50. Dielectric constant, at room temperature, has been found to increase with increasing substituent concentration upto x= 0.30 and thereafter it decreases with increasing xupto 0.50. Orientational and space charge polarizations contribute to the dielectric behaviour of these materials.