Half Antiperovskites. III. Crystallographic and Electronic Structure Effects in Sn_2−xIn_xCo₃S₂

Abstract

Abstract Half antiperovskites were investigated within the series Sn 2−x In x Co 3 S 2 by X‐ray diffraction, thermal analysis, and DFT band structure calculations. The shandite type structure was confirmed from powder and single crystal diffraction for the studied compounds. Co orders like Ni in the previously studied InNi 3/2 S. SnCo 3/2 S is metrically pseudo cubic and can easily be deduced from the antiperovskite MgCo 3 C. The Curie temperature T c = −97 °C of SnCo 3/2 S was confirmed by calorimetric data. Its electronic structure indicates a spin ${1 \over 2}$ type I A half metallic ground state. Upon In doping the crystal structure becomes hexagonally distorted towards a higher c hex /a hex relation. The Curie temperature rapidly falls below −135 °C for x (In) = 0.4. A metal to semiconductor transition is predicted for ordered InSnCo 3 S 2 from its electronic band structure. For InCo 3/2 S a non magnetic metallic ground state is found.