Thermodynamic properties of the ternary Na–Cu–Te alloy by electromotive force measurements with an alumina solid electrolyte

Activity coefficients for sodium metal in the equimolar CuTe alloy were measured up to 54 at. % sodium at 913 K. The experimental technique consisted of an alloy concentration cell with a solid alumina electrolyte. The results indicated that the solutions were Henrian up to 1 at. % sodium. In addition, for dilute sodium concentrations, there is an exosolution effect. However, for the more concentrated solutions, there is some ionicity. Keywords: tellurides, thermodynamics, alkali metals.