Thermal and Electronic Transport Properties of the Half-Heusler Phase ScNiSb.

Thermoelectric properties of the half-Heusler phase ScNiSb (space group 4 ¯ 3) were studied on a polycrystalline single-phase sample obtained by arc-melting and spark-plasma-sintering techniques. Measurements of the thermopower, electrical resistivity, and thermal conductivity were performed in the wide temperature range 2-950 K. The material appeared as a -type conductor, with a fairly large, positive Seebeck coefficient of about 240 μV K near 450 K. Nevertheless, the measured electrical resistivity values were relatively high (83 μΩm at 350 K), resulting in a rather small magnitude of the power factor (less than 1 × 10 W m K) in the temperature range examined. Furthermore, the thermal conductivity was high, with a local minimum of about 6 W m K occurring near 600 K. As a result, the dimensionless thermoelectric figure of merit showed a maximum of 0.1 at 810 K. This work suggests that ScNiSb could be a promising base compound for obtaining thermoelectric materials for energy conversion at high temperatures.