Materials (May 2019)

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

  • Karol Synoradzki,
  • Kamil Ciesielski,
  • Igor Veremchuk,
  • Horst Borrmann,
  • Przemysław Skokowski,
  • Damian Szymański,
  • Yuri Grin,
  • Dariusz Kaczorowski

DOI
https://doi.org/10.3390/ma12101723
Journal volume & issue
Vol. 12, no. 10
p. 1723

Abstract

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Thermoelectric properties of the half-Heusler phase ScNiSb (space group F 4 ¯ 3m) 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 p-type conductor, with a fairly large, positive Seebeck coefficient of about 240 μV K−1 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 × 10−3 W m−1 K−2) in the temperature range examined. Furthermore, the thermal conductivity was high, with a local minimum of about 6 W m−1 K−1 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.

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