An investigation of the Tl–Te–I system and crystal structure of the Tl5Te2I

Abstract

The phase relations in the Tl–Te–I system have been experimentally investigated over the entire concentration range mainly by thermal analysis (DTA), X-ray diffraction (XRD) applied to equilibrated alloys. The isothermal section at 300 K, liquidus surface projection and the phase diagrams of the six isopleth sections have been constructed. The homogeneity ranges and primary crystallization fields for the all phases, as well as, the character and temperature of non- and monovariant equilibria were determined in the system. The crystal structure of the Tl5Te2I compound has been determined by single crystal X-Ray diffraction. It is found to be stoichiometric and isostructural which crystallize in the In5Bi3 structure type with four formula units in the tetragonal system, space group I4/mcm, а = 9.001(2); c = 13.291(4) Å.