Thermoelectric properties of perovskite-type oxide La1-xSr xCoO3 (x = 0, 0.1) prepared by solid state reactions

P-type perovskite oxides La1-xSr xCoO3 (x = 0, 0.1) have been prepared by solid state reactions. The phase structures and microstructures of the oxides were investigated and the Seebeck coefficient, electrical conductivity and thermal conductivity were measured from room temperature to 773 K. It was found that Sr substitution can improve the electrical conductivity but significantly reduce the Seebeck coefficient of La1-xSr xCoO3. The thermal conductivity was also reduced after Sr substitution. In the measured temperature range, the maximum ZT values of the oxides were 0.015 at 673 K for x = 0 and 0.013 at 423 K for x = 0.1. Optimizations of the materials are necessary for the practical applications of La1-xSr xCoO3 oxides