Thermal stability of giant thermoelectric seebeck coefficient for SrTiO3/SrTi0.8Nb0.2O3 superlattices at 900 K

Herein we report the carrier transport properties of [(SrTi0O(3))(x)/(SrTi0.8Nb0.2O3)(1)](20) (x = 0-50) superlattices at high temperatures (T = 300-900K). Significant structural changes were not observed in the superlattices after annealing at 900K in a vacuum. The Seebeck coefficient of the [(SrTiO3)(20)/(SrTi0.8Nb0.2O3)(1)](20) superlattice, which was 300 mu V.K-1 at room temperature, gradually increased with temperature and reached 450 mu V.K-1 at 900 K, which is similar to 3 times larger than that of bulk SrTi0.8Nb0.2O3. These observations provide clear evidence that the superlattice is stable and exhibits a giant Seebeck coefficient even at high temperature. (C) 2008 The Japan Society of Applied Physics.