Alternating-Current Electrical Conduction Properties of DyCoO3 Ceramics

Abstract

Abstract The ac , dc conductivity and dielectric properties of DyCoO 3 were reported in the temperature range of 77 - 300Kand in the frequency range of 20 Hz - 100 kHz. It was observed that at low temperature, ac conductivity is much higherthna dc conductivity and the hopping carrier between localized states near the Fermi level was the dominant loss mechanism.A comparison of the measured ac conductivity ( ) was made with some of the models of hopping conductivity of theproposed earlier in the literature. It was observed that in DyCoO 3 the measured ac conductivity, over the entire frequencyand temperature region, can be explained reasonably well by assuming two contributions 1 ( ) and 2 ( ) to the measured ( ). The first, 1 ( ), which dominates at low temperature, may be due to impurity conduction in a small polaron; theecond,s 2 ( ), which dominates at higher temperatures, depending on the frequency of measurements, may be due to thehopping of a small polaron and is reasonable for the dielectric relaxation peak.Key words ac conductivity , dielectric relaxation, small polaron.