Large thermoelectric response of metallic perovskites:: Sr1-xLaxTiO3 (0≤x≤0.1) -: art. no. 113104

Thermoelectric properties have been investigated for single crystals of Sr1-xLaxTiO3 for 0 much less thanx much less than0.1. We have found a large power factor (defined as PF = S-2/rho, S and rho being the Seebeck coefficient and resistivity, respectively), 28-36 muW/(K-2 cm), at room temperature in the metallic region with carrier density (n) of (0.2-2)x10(21) cm(-3) The observed PF is comparable to that of Bi2Te3 with much lower n (similar to1 x 10(19) cm(-3)). Such an unexpectedly large PF or S at the metallic carrier density is ascribed to the orbital degeneracy (threefold) of the Ti 3d-t(2g) conduction band and the relatively large effective mass of conduction electrons as well as to the large energy-dependent scattering rate.