Synthesis and Characterization of Ba₂SnTe₅: A New Zintl Phase Containing Unique One-Dimensional Chains of (SnTe₃)^2- and Dimeric Units of (Te₂)^2-

Abstract

Ba2SnTe5, a novel alkaline-earth-metal tin telluride has been synthesized from a potassium polytelluride salt. Single-crystal X-ray diffraction analysis shows that this compound is a Zintl phase containing unique one-dimensional “Zweireinfach”-chains of corner-sharing SnTe4 tetrahedra and isolated (Te2)2- dimers. It represents the first ternary alkaline-earth-metal telluride synthesized from a polytelluride flux. Band calculations indicate strong covalent bonding between the Sn and Te within the chain. The interactions between the dimers and the chains are weak and repulsive.