High-temperature thermopower and conductivity of La 1− xBa xMnO 3 (0.02⩽ x⩽0.35)

Abstract

Thermopower and conductivity are measured for the perovskite-like manganite La 1− x Ba x MnO 3 (0.02⩽ x⩽0.35) in the temperature range 200–950°C and oxygen pressure varying between 10 −11 and 0.5 atm. The data for thermopower and electrical conductivity indicate a transport mechanism dominated by adiabatic hopes of small polarons. The high-temperature limit for the thermopower is mainly defined by the spin contribution while configurational contribution does not depend essentially on the doping level. Changes in the conductivity with doping are shown to reflect variations in the mobility of charge carriers.