Thermoelectric Properties of Combustion-Synthesized Lanthanum-Doped Strontium Titanate

Abstract

The possibility of combustion synthesis of perovskite-oxide thermoelectric materials with the attendant saving of energy and time and without deterioration in the thermoelectric properties was investigated by evaluating the thermoelectric properties of lanthanum-doped strontium titanate (Sr_1−xLa_xTiO₃, 0≤x≤0.1). The materials were successfully combustion synthesized and spark plasma sintered with 98.0–99.6% of true density, and their thermoelectric properties were evaluated from room temperature to 850 K. The optimal lanthanum doping amount ratio x in the considered temperature range was from 0.06 to 0.08, in which Sr_0.92La_0.08TiO₃ sample showed the maximum ZT of 0.22 at 800 K. This value was close to the highest recorded ZT at the same temperature up to now, and the ZT of most samples are higher than those synthesized by the conventional solid state reaction method. Thus, combustion synthesis is promising for producing perovskite-oxide thermoelectric materials for high-temperature application.