Thermoelectric properties of La-doped BaSi2

The authors tried to enhance the thermoelectric figure of merit of BaSi2 by doping La. Polycrystalline samples of La-doped BaSi2: Ba1-xLaxSi2 (0 <= x <= 0.08) were prepared and characterized. The effect of La-doping was investigated by measuring the thermoelectric properties above room temperature to 973 K. La could dissolve in BaSi2 up to around x = 0.03, while LaSi2 appeared as the second phase in the higher x range. Both the electrical resistivity and thermal conductivity of the La-doped samples were lower than those of the non-doped Bask. Ba1-xLaxSi2 (x = 0.02) indicated the largest power factor and dimensionless figure of merit (ZT). The ZT value was 0.07 at 970 K, which was approximately 7 times larger than that of non-doped BaSi2.