Thermoelectric properties of Yb-La-Nb-doped SrTiO3

Yb 2 Ti 2 O 7 exhibits ferromagnetic and magnetic properties , which are expected to exert a discernible influence on the thermoelectric properties of SrTiO 3 composite. The La-Yb-Nb-doped SrTiO 3 powders, synthesized via the hydrothermal method , were prepressed and then buried in carbon powder before being sintered in a muffle furnace at 1573 K for 5 h. The Yb dopant precipitated during the sintering process, leading to the in-situ formation of Yb 2 Ti 2 O 7 . The content of Yb 2 Ti 2 O 7 increased with an increasing Yb concentration, resulting in a reduction in thermal conductivity and grain boundary potentials, and an increase in the peak electrical conductivity . The La and Nb dopants affect the electrical conductivity and the Seebeck coefficient. Therefore, by controlling the La, Nb, and Yb ratios, the La8Yb2Nb15 sample achieved the largest power factor ( PF ) value of 0.9 mWm −1 K −2 and a low thermal conductivity of 2.9 W m −1 K −1 , resulting in a high ZT value of 0.32 at 1000 K.