Electrochemical determination of thermodynamic properties of saturated solid solutions of Hg2GeSe3, Hg2GeSe4, Ag2Hg3GeSe6, and Ag1.4Hg1.3GeSe6 compounds in the Ag–Hg–Ge–Se system

Abstract

Triangulation of the Ag–Hg–Ge–Se system in the vicinity of GeSe2, HgSe, Hg2GeSe3, Hg2GeSe4, Ag2Hg3GeSe6, and Ag1.4Hg1.3GeSe6 compounds and selenium was performed using X-ray diffraction and differential thermal analysis methods. The spatial position of the determined four-phase regions regarding figurative point of silver was used to write the equations of virtual potential-forming chemical reactions. Potential-forming processes were performed in electrochemical cells (ECCs) of the type (−) C | Ag | Ag3GeS3I glass | D | C (+) where C are the inert (graphite) electrodes, Ag and D are the electrodes of the ECCs, D represents equilibrium four-phase alloys, and Ag3GeS3I glass is a membrane with purely ionic Ag+ conductivity. The linear dependences of the EMF of galvanic cells on temperature in the range of 425–455 K were used to calculate the standard thermodynamic values of saturated solid solutions of Hg2GeSe3, Hg2GeSe4, Ag2Hg3GeSe6, and Ag1.4Hg1.3GeSe6 compounds.