Thermoelectric properties of N-type and P-type barium stannates prepared by elemental substitution

Abstract

Thermoelectric properties of N-type and P-type ceramics based on BaSnO₃ were investigated at high temperatures. The power factor of the N-type degenerate semiconducting Ba_1-xLa_xSnO₃ ceramics with x=0.002-0.070 was maximized for x=0.005 and the value was 4.3*10^-4 Wm^-1K^-2 at 1070 K. The substitution of Sr for Ba brought about the systematic decrease in the power factor. The thermal conductivity for the Ba_0.995La_0.005SnO₃ ceramic was 4.7 Wm^-1K^-1 at 1070 K, leading to a ZT value of 0.1. The power factor of the P-type BaSn_1-xCo_xO₃ ceramics with x=0.03-0.15, which were thermally-activated semiconductors, did not largely depend on the Co content and the values were 2*10^-11-3*10^-7 Wm^-1K^-2 in the temperature range of 370-1070 K.