Transport phenomena in La0.8Ba0.2MnO3 single crystal: evidence for activation to mobility edge

Abstract We have studied the magnetic and transport properties of La 0.8 Ba 0.2 MnO 3 single crystal over temperature range 77–400 K in magnetic fields up to 15 kOe. Near the Curie temperature, both the resistivity, the thermopower, and the normal Hall coefficient R 0 reach the maximal value, R 0 >0 and the Hall mobility is constant. The data indicate that the holes activated to mobility edge dominate in conduction. The singlesite polaron picture is inconsistent with our data on magnetoresistance and magnetothermopower.