Phase Equilibria in the Tl2Te-SiTe2 and Tl2SiTe3-Сd(Hg)Te Systems

Component interaction in the Tl2Te 2 Te - SiTe2 2 and Tl2SiTe3 2 SiTe 3 - Cd(Hg)Te systems was investigated by X-ray diffraction (XRD), differential thermal analysis (DTA), and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) methods. The formation of four new ternary tellurides Tl18SiTe11, 18 SiTe 11 , Tl4SiTe4, 4 SiTe 4 , Tl2SiTe3, 2 SiTe 3 , and Tl2Si2Te5, 2 Si 2 Te 5 , was found in the Tl2Te 2 Te - SiTe2 2 system. The Tl18SiTe11 18 SiTe 11 and Tl2SiTe3 2 SiTe 3 compounds are formed congruently at 778 and 618 K, and Tl4SiTe4 4 SiTe 4 and Tl2Si2Te5 2 Si 2 Te 5 form incongruently at 546 and 584 K, respectively. Quaternary compounds Tl2CdSiTe4 2 CdSiTe 4 and Tl2HgSiTe4 2 HgSiTe 4 that form in the Tl2SiTe3 2 SiTe 3 - Cd(Hg)Te systems crystallize in the tetragonal space group I - 42 m & acy; nd melt incongruently at 826 and 738 K, respectively. Each compound has a homogeneity region up to 5 mol.% from the Tl2SiTe3 2 SiTe 3 side at 520 K.