Discovery of a Slater-Pauling semiconductor ZrRu${}_{1.5}$Sb with promising thermoelectric properties

Cubic half- and full-Heusler compounds with respectively 18 and 24 valence electrons exhibit semiconducting behaviors according to the Slater-Pauling rule. In this work, a half-Heusler-like ZrRu${}_{1.5}$Sb semiconductor with the space group F$\overline{4}$3m is discovered based on the Slater-Pauling rule. The ZrRu${}_{1.5}$Sb compound has 21 valence electrons per chemical formula and each atom has six valence electrons on average, showing a p-type conduction with a dimensionless thermoelectric figure of merit zT ≈0.2 at 973 K. By adjusting the Ru content, both p-type (x ≤ 0.5) and n-type (x > 0.5) semiconductors are realized in the ZrRu${}_{1+x}$Sb solid solution. Following this way, other half-Heusler-like semiconductors, such as ZrRu${}_{1.30}$Ni${}_{0.10}$Sb, ZrRu${}_{1.40}$Ni${}_{0.05}$Sb, and ZrRu${}_{1.30}$Ni${}_{0.05}$Sb, are also successfully designed and synthesized, demonstrating the effectiveness and practicality of our strategy to explore Slater-Pauling semiconductors. Furthermore, these half-Heusler-like semiconductors show promising potential as thermoelectric materials. The p-type ZrRu${}_{1.4}$Sb and n-type ZrRu${}_{1.7}$Sb samples have zT values of 0.38 at 973 K and 0.25 at 773 K, respectively, offering superior base materials for further optimizing their thermoelectric properties. The discovery of ZrRu${}_{1.5}$Sb-based thermoelectric semiconductors demonstrates the great potential to design Slater-Pauling phases with exotic physical properties. (© 2022 Wiley‐VCH GmbH)