Low-temperature ac conductivity of La0.95Sr0.05MnO3.08

Abstract

The ac conductivity of La0.95Sr0.05MnO3.08 has been measured at temperatures between 20-77 K, and for frequencies up to 100 kHz. A comparison of the measured ac conductivity () has been made with some of the models of hopping conductivity proposed earlier in the literature. It is observed that in La0.95Sr0.05MnO3.08 the measured ac conductivity, over the entire frequency and temperature region, can be explained reasonably well by assuming two contributions 1() and 2() to the measured (). The first, 1(), which dominates at low temperatures (T<40 K), may be due to the impurity conduction in small polarons of ligand holes (L); the second, 2(), which dominates at higher temperatures (T>40 K), depending on the frequency of measurement, may be due to hopping of small polarons and is responsible for the activated dielectric loss peak.