ІЗОТЕРМІЧНІ ПЕРЕРІЗИ ПРИ 770 K ТА СКЛОУТВОРЕННЯ У СИСТЕМАХ AgCl(I) – Ga2S3 – La2S3

Анотація

For the investigation of the phase equilibria in the systems AgCl(I) – La₂S₃ – Ga₂S₃ 30 samples were synthesized for each of system. The samples were studied by X-ray diffraction (XRD) and differential thermal analyses (DTA). Diffraction patterns were recorded on DRON 4-13 diffractometer, CuK_α radiation, step scan 0.05º, exposure time 2 s. The analysis of the diffraction patterns was performed using PowderCell-2 software package. The DTA curves were recorded using Pt/Pt-Rh thermocouples at a combination of a Thermodent regulated heating furnace and a H307-1 XY recorder set. Phase equilibria in AgCl(I) – La₂S₃ –  Ga₂S₃ system at 770 K were built from the X-ray analysis results. In the quasiternary systems, small one-phase regions are formed based on Ga₂S₃, S.G. Cc, a = 1.1136 (2), b = 0.6407 (2), c = 0.7038 (3) nm, b  = 121.22°, La₂S₃, S.G. Pnma, a = 0.7560 (3), b = 0.4291 (1), c = 1.5850 (2) nm, AgCl, S.G. F-43m, a = 0.5617 (5) nm, AgI, S.G. F-43m, a = 0.6485 (5) nm. In addition in the quasiternary systems the existence of two quasibinary systems AgCl(I) – LaGaS₃ and AgCl(I) – La₃Ga_1,67S₇ was found. They triangulate quasiternary systems on three subsystems AgCl(I) – La₂S₃ – LaGaS₃, AgCl(I) – LaGaS₃ – La₃Ga_1,67S₇, AgCl(I) – La₂S₃ – La₃Ga_1,67S₇. In the La₂S₃ – Ga₂S₃ system, the existence of ternary compounds LaGaS₃, orthorombic system, S.G. Pna2₁, а = 1,5175(3), b = 1,0568(6), с = 1,2829(7) nm, β = 137,56 ̊, La₃Ga_1,67S₇, structural type Ce₃Al_1,67S₇, S.G. P6₃, a = 0,9935(3), c = 0,6013(6) nm was confirmed. There are very small one-phase regions based on them. The quaternary compounds were not found. The glasses in the AgCl(I) – Ga₂S₃ – La₂S₃ systems have orange-red color, transparent. The glass-forming regions in the AgCl(I) - Ga₂S₃ - La₂S₃ systems locate within the 50-75 mol.% Ga₂S₃ in the system La₂S₃ – Ga₂S₃ and extend into the concentration triangle till 5 mol.% AgCl(I). The values of the Hruby factor for the glassy specimens located within the range of 50-75 mol% Ga₂S₃ in the La₂S₃ – Ga₂S₃ system were found and found out that they are not significant and these samples do not have high glass-forming ability. But the samples obtained three years ago retain their glassy conditions and can be used in semiconductor technology.