Tsisar O. The Tl2X–CIII2X3–DIVX2 systems (CIII – Ga, In; DIV – Ge, Sn; X – S, Se): phase equilibria, glass formation and properties of intermediate phases

The thesis contains the results of the investigation of the phase equilibria and glass formation in quasi-ternary systems based on Tl, Ga(In) and Ge(Sn) chalcogenides. Isothermal sections of 8 quasi-ternary systems Tl2X–CIII2X3–DIVX2 (CIII – Ga, In; DIV – Ge, Sn; X – S, Se) at 520 K were investigated for the first time. The existence of 9 new compounds (Tl2Ga20S31, Tl2Ga2GeSe6, TlGaGe2Se6, ~Tl7GaGeSe7, ~Tl5InGe2S8, Tl2In2GeS6, ~Tl2In2Ge3S10, Tl2Ga2SnSe6, ~Tl5,6InSn6,7S17,6) was established in the systems under study. The crystal structure of compounds: Tl2Ga20S31, TlGaGe3S8, TlInGe2Se6 (own structure type), TlGaSn2Se6 and TlInGe2S6 was studied. Electronic structure, optical and non-linear optical properties of the compounds TlCIIIDIV2X6 were investigated. The region of the existence of glasses in the Tl2X–Ga(In)2X3–GeX2 systems was determined by quenching the melts from 1300 K. Thermal, optical and non-linear optical properties of glasses were determined.