Akademik Məlumat İdarəetmə Sistemi
Russian Chemical Bulletin, vol.74, no.5, pp.1237-1246, 2025 (SCI-Expanded, Scopus)
Phase equilibria in the Ag2Se—Ag8SiSe6—Ag8SnSe6 system were studied by differential thermal analysis (DTA), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM). The diagram temperature—composition of the Ag8SiSe6—Ag8SnSe6 boundary system, a number of polythermal sections, isothermal sections of the phase diagram at 300, 1100, and 1150 K, and projection of the liquidus surface were constructed. The Ag8SiSe6—Ag8SnSe6 side system is quasi-binary and characterized by the formation of a continuous series of solid solutions (δ-phase) between high-temperature cubic modifications of the initial compounds. When solid solutions are formed, the temperatures of polymorphic transformations of both compounds decrease, which leads to the stabilization of the ion-conducting cubic phase in a composition range of 10–65 mol.% Ag8SnSe6 at room temperature. Rather narrow (2–3 mol.%) regions of solid solutions based on the low-temperature and intermediate modifications of Ag8SiSe6 were revealed, whereas up to 20 mol.% solid solutions based on the low-temperature modification of Ag8SnSe6 were identified. The liquidus surface of the system under study consists of two fields corresponding to the primary crystallization of the δ-phase and solid solutions based on high-temperature Ag2Se. Phase transitions associated with polymorphism of the initial compounds and related phases based are observed in the subsolidus part of the system.