Experimental thermodynamic study of intermetallic phases in the binary Ag–Te system by an improved EMF method

A thermodynamic study of the solid two-phase regions of the binary Ag–Te system was made by an improved EMF method, using fast ion conductor RbAg4I5 as the solid electrolyte. The EMF measurements were made on three galvanic cells: [Ag | RbAg4I5 | Ag5Te3 + Te], [Ag | RbAg4I5 | Ag5Te3 + Ag1.9Te] and [Ag | RbAg4I5 | Ag1.9Te + Ag2Te]. on the results obtained, the EMF for each equilibrium phase assembly was expressed as a function of temperature, in the different regions of thermal stability of the substances. By using the observed EMF and temperature relations, the thermodynamic functions of the stoichiometric equilibrium phase assemblages: Ag5Te3–Te, Ag5Te3–Ag1.9Te, Ag5Te3–Ag2Te and Ag2Te–Ag1.9Te, in the low-temperature range 22–204 °C, as well as phase transformation temperatures, have been determined. Agreement between the results obtained and the literature values were established.