Fabrication and high-temperature thermoelectric properties of Ti-doped Sr0.9La0.1TiO3 ceramics

Ti-doped Sr0.9La0.1TiO3 ceramics with high density were successfully prepared in argon atmosphere by conventional solid state reaction. The influences of titanium doping content on the microstructure and thermoelectric properties were investigated. The results showed that titanium was oxidized during the calcination procedure. TiO2 phase survived and coexisted with Sr0.9La0.1TiO3 phase in the sintered ceramics. The Seebeck coefficients were increased from −163 to −259 μV/K as the temperature increased from 350 K to 1073 K. The thermal conductivity can be significantly reduced by doping Ti. Thermoelectric figure of merit (ZT) first decreased and then increased with increasing Ti doping content. Ceramics showed the best thermoelectric properties when Ti doping amount was 5 wt%, the maximum PF was 7.13 μW/K2/cm, and ZT value was 0.144 at 1073 K.