Thermoelectric properties of non-doped and Y-doped SrTiO3 polycrystals synthesized by polymerized complex process and hot pressing

Synthesis of non-doped and Y-doped SrTiO3 polycrystals was tried by the polymerized complex (PC) process and the subsequent hot pressing at 1473 K and 1673 K. The effects of hot pressing temperature on thermoelectric properties of these SrTiO3 sintered bulks were investigated. The PC process could provide the powder precursor with perovskite SrTiO3 structure even when Y was substituted for Sr site. And then, the SrTiO3 phase was mostly maintained after hot pressing. The Y doping slightly accelerated densification of compacts during the hot pressing. From these results, among the polycrystalline bulks fabricated in this study, the Sr0.9Y0.1TiO3 sample hot-pressed at 1673 K showed the maximum dimensionless figure of merit, 0.146 at 870 K. This figure of merit is lower than that of earlier results [H. Muta, K. Kurosaki, S. Yamanaka, J. Alloys Compd. 350 (2003) 292-295].