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Mixed cation Ag 2 S-Tl 2 S-GeS 2 glasses containing 40 and 50 mol% of metal sulfide have been synthesized and analyzed for the first time using thermal analysis, conductivity measurements and Raman spectroscopy. The composition dependences of the ionic conductivity and glass transition temperature T g showed the presence of classical mixed cation effect with the minimum of both glass transition temperature and room temperature conductivity and the activation energy maximum centered at r = Ag/(Tl + Ag) ≈ 0.2. Raman spectroscopy measurements reveal that the structure of the mixed glasses is not a simple mixture of the end-members, pure thallium (r = 0) and silver (r = 1) thiogermanates. The edge-sharing ES-Ge 2 S 6 dimers and corner-sharing CS-Ge n S 3n+1 (n = 2 or 3) oligomers disappear more quickly than is predicted by the stoichiometry relations. The systematic evolution of the vibrational properties as a function of the silver fraction r also suggests that the both cations are not separated spatially in the glass network but rather located in close proximity to each other.

Glass‐forming region, macroscopic properties, and electrical conductivity changes are systematically studied in the MY–Ga2S3–GeS2 systems, where M = Na, K, Rb and Y = Cl, Br, I, as a function of alkali concentration, MY chemical composition, and Ga2S3/GeS2 ratio using two composition lines: series A – (MY)x(Ga2S3)0.2–0.2x(GeS2)0.8–0.8x and series B – (MY)x(Ga2S3)0.2 + 0.2x(GeS2)0.8−1.2x. Glasses of series B are characterized by higher maximum MY concentration, increasing with the cation radius up to 66.7 mol% in case of RbCl. The halide nature is found to be less significant for the vitrification ability. The density of samples varies monotonically between the two end‐members of each series. Glass transition temperature decreases with increasing alkali concentration, ranging from 426 °C (x = 0) to 237 °C for (RbCl)67(Ga2S3)33 sample. The conductivity of MY–Ga2S3–GeS2 glasses decreases with increasing cation radius. The Ga2S3/GeS2 ratio and the halide nature affect the conductivity weakly.

Raman spectra of (MY) x (Ga2S3)0.2−0.2x (GeS2)0.8−0.8x pseudo-ternary glassy systems (M = Na, K, Rb; Y = Cl, Br, I) were investigated systematically as a function of MY nature and alkali content. Raman spectroscopy of the Ga3S3-GeS2 glassy matrix shows a complicated local structure: corner-sharing CS- and edge-sharing ES-GeS4/2 tetrahedra, Ga-S triclusters and ETH-Ga2S6/2 ethane-like units. The Ga2S6/2 population decreases with increasing x related to a substitution of some bridging sulfur atoms around central Ga by terminal Y species with a respective decrease of the network rigidity. The formation of mixed Ga-(S,Y) environment is affected by the M+ ion size and the MY concentration.