Interaction of argyrodite family compounds with the chalcogenides of II-b elements

Using the results of DTA, X-ray phase analysis and metallography, we constructed phase diagrams of a series of sections of quasi-ternary systems Ag2X–AIIX–BIVX2 formed by the compounds of the argyrodite family, Ag8BIVX6, and by AIIX compounds (AII = Zn, Cd; BIV = Si, Ge, Sn; X = S, Se). The formation of solid solution ranges of ternary argyrodites is established; the maximum extent of solid solutions is observed at the temperatures of non-variant processes and decreases substantially with temperature decrease. The eutectic interaction is typical of zinc-containing sections. Both peritectic (Ag8Si(Ge)S6–CdS, Ag8SiSe6–CdSe) and eutectic (Ag8SnS6–CdS, Ag8Ge(Sn)Se6–CdSe) type of interaction is found among cadmium-containing systems. The possibility of obtaining eutectic crystals by directed crystallization of the melt of eutectic point composition is shown.