Sn/Sb atom ordering in the ternary stannide-antimonide TiSnSb

TiSnSb was prepared by reacting the elements Ti and Sb in an Sn flux at 500°C. Alternatively, TiSnSb can be synthesized from the elements in the stoichiometric 1:1:1 ratio at 850°C. According to our single crystal data, TiSnSb forms the Mg₂Cu type, orthorhombic space group Fddd, with a=5.4892(7), b=9.845(1), and c=19.151(3) Å (Z=16). As evident from both our structure refinements and our electronic structure calculations, the two crystallographically independent positions of the Mg atoms in the Mg₂Cu type are not statistically occupied by the Sn and Sb atoms in the TiSnSb structure. Structural and electronic similarities to and differences from TiSb₂ and NbSnSb (both CuAl₂ type) are discussed. Supporting the electronic structure calculations, physical property measurements revealed the metallic character of TiSnSb, with holes being the dominant charge carriers.