Bismuth as a Reactive Solvent in the Synthesis of Multicomponent Transition-Metal-Bearing Bismuthides.

Abstract

Employment of liquid bismuth (Bi) allows the facile single-crystal growth of compounds containing elements with high melting points, provided that these elements have reasonably high solubility in Bi. Utilization of the Bi flux approach yielded two new ternary bismuthides, SrNi0.17(1)Bi2 [a defect variant of the BaCuSn2 type, space group Cmcm, a = 4.879(2) Å, b = 17.580(6) Å, and c = 4.696(2) Å] and CaTi3Bi4 [NdTi3(Sn0.1Sb0.9)4 structure type, space group Fmmm, a = 5.6295(7) Å, b = 9.8389(1) Å, and c = 23.905(3) Å]. In addition, the ternary antimonide CaV3Sb4, isostructural with CaTi3Bi4, was synthesized from antimony (Sb) flux, and analyzed with the goal of validating structural assessment of the bismuthide analogue, where the X-ray crystallographic work proved to be very challenging. All synthesized compounds exhibit complex crystal structures featuring quasi-two-dimensional building blocks of different topologies. First-principle calculations reveal hypervalent bonding in the homoatomic Bi subunits. Physical property measurements indicate metallic conductivity and the absence of localized magnetism in the studied compounds.