La and Nd Co-doped Effect on Thermoelectric Properties of SrTiO3 Ceramics

Abstract

Ceramic samples of Sr1-x-yLaxNdyTiO3 with different La and Nd concentration have been synthesized by conventional solid state reaction technique, and their thermoelectric properties have been investigated. X-ray diffraction characterization confirms that the main crystal structure is of perovskite. SEM images indicate all ceramic samples are dense and compact, and the grain size increase with the doping content increasing. Electrical conductivity and Seebeck coefficient of samples have been measured in the temperature range between 300 K and 1100 K. With increasing of doping concentration, electrical resistivity decreases, and reaches 3.8 mΩ·cm for sample x=0.10 at 1045 K. The absolute Seebeck coefficients increase monotonically with increasing temperature in the whole temperature range. Sample with x=y=0.05 exhibits the highest absolute Seebeck coefficient. The sample with x=y=0.10 exhibits the maximum power factor 14 μWcm-1K-2 at 456 K.