Application of solid electrolytes α-AgI and RbAg4I5 for refining phase diagrams and determining standard thermodynamic functions of compounds in silver-containing systems

Standard thermodynamic properties of minerals and phases of ternary systems Ag-Au-X (X = S, Se, Te) are determined by measuring the EMF in the cells with a common gas space and Ag4RbI5 as the solid electrolyte. By this means, thermodynamic functions of the following minerals and phases are determined: Au2S, Ag3AuS2 (uytenbogaardtite), AgAuS (petrovskaite), Ag2Se (naumannite), AuSe, Ag3AuSe2 (fischesserite), and Ag5Te3 (stuetzite). Thermodynamics of a pyrite-pyrrhotite equilibrium in the Ag-Fe-S system is studied in a cell with a solid electrolyte based on silver iodide at 500–730 K and atmospheric pressure.