Phase equilibria in the pseudoternary system Ag2Se-Ag8GeSe6-Ag8SnSe6

Phase equilibria in the Ag2Se-Ag8GeSe6-Ag8SnSe6 system have been studied by differential thermal analysis, X-ray diffraction, scanning electron microscopy, and emf measurements on concentration cells with Ag4RbI5 as a solid electrolyte. We have mapped out the T-x phase diagram of the constituent binary system Ag8GeSe6-Ag8SnSe6, those of two mutually perpendicular sections, and the liquidus projection. The two crystalline phases of the constituent selenides Ag8GeSe6 and Ag8SnSe6 have been shown to form a continuous series of solid solutions. The Ag2Se-Ag8GeSe6-Ag8SnSe6 system is a pseudoternary section through the quaternary system Ag-Ge-Sn-Se, and its phase diagram has a univariant eutectic.