Valence compensated perovskite oxide system Ca1-xLaxTi1-xCrxO3 - Part II -Electrical transport behavior

Electrical transport behaviour of the valence compensated system Ca1-xLaxTi 1-xCrxO3 (x less than or equal to 0.50) has been investigated by studying t he Seebeck co-efficient, DC and AC conductivity as a function of temperatur e. Seebeck co-efficient, DC conductivity of different compositions has been measured in the temperature range 300 K-1000 K. AC conductivity for differ ent compositions were determined in the temperature range 100-550 K and fre quency range 10 Hz-10 MHz. Positive values of Seebeck co-efficient show tha t holes are the majority charge carriers. Conduction seems to occur by corr elated barrier hopping of holes among Cr3+ and Cr4+ ions or V-o(.) and V-o( ..). Almost equal values of activation energies obtained for DC conductivit y and dielectric relaxation process show that both the processes occur by t he same mechanism. (C) 2001 Kluwer Academic Publishers.