BaGe8As14: a semiconducting sodalite-type compound

Chem Commun (Camb). 2021 Feb 7;57(11):1332-1335. doi: 10.1039/d0cc07813a. Epub 2021 Jan 11.

Abstract

A new sodalite-type compound, namely BaGe8As14 was synthesized via solid-state reactions and structurally characterized with single crystal X-ray diffraction (space group I4[combining macron]3m). Vertex-sharing GeAs4-tetrahedra form β-cages with additional Ge/As-mixed sites located slightly above or below the six-membered rings. The structure is similar to the borate mineral rhodizite. Barium atoms are disordered due to a slight shift off the centers of large β-cages. This partially disordered structure together with a narrow bandgap of 0.43 eV in line with low resistivity (2 × 10-2Ω cm), and a high carrier concentration (1.6 × 1020 cm-3) at 300 K qualifies BaGe8As14 as a potential thermoelectric material.