Danyliuk I. Phase equilibria and the properties of intermediate phases of quasi-ternary systems based on Ag2X, BIII2X3, R2X3 (BIII - Ga, In; R - Y, La, Pr, Tb, Ho, Er; X - S, Se)

The phase equilibria in quasi-ternary systems Ag2X–Ga2X3–In2X3 (X - S, Se) and La2S3–Er2S3–Ga2S3 were investigated for the first time. The 8 diagrams of quasi-binary systems, 14 polythermal sections, three isothermal sections (820, 870 K) and two projection of the liquidus surface on the concentration triangle were constructed. The fields of the primary crystallization phases and the types and coordinates of invariant and monovariant equilibria were determined. The ranges of solid solutions based on binary, ternary and quaternary phases were determined. The crystal structure of the solid solutions based on 2T AgIn5Se8 was investigated. The existence of a new quaternary phase La1,59Er1,41Ga1,67S7 and its analogues La1,86Tb1,14Ga1,67S7, Pr2,48Tb0,52Ga1,67S7, La1,5Y1,5Ga1,67S7, Pr1,5Ho1,5Ga1,67S7 which crystallize in the hexagonal system (S.G. P63), structural type Ce3Al1,67S7, was determined. The single crystals of the phases (Ga0,55In0,45)2S3, (Ga0,6In0,4)2Se3 and erbium doped were obtained for the first time and their properties were investigated. The glasses of the system La2S3–Er2S3–Ga2S3 were obtained for the first time and their photoluminescence properties were investigated.