Thermodynamic study of the Cu-As-S system by EMF measurements with Cu4RbCl3I2 as a solid electrolyte

Abstract

The Cu-As-S system has been studied at temperatures from 300 to 370 K using emf measurements with Cu4RbCl3I2 as a Cu+ ion conducting solid electrolyte, and its subsolidus phase diagram has been mapped out, including the ternary compounds Cu3AsS4, Cu6As4S9, Cu4As2S5, Cu3AsS3, and CuAsS. From the emf data, we have calculated the partial molar thermodynamic functions (\(\Delta \bar G\), \(\Delta \bar H\), and \(\Delta \bar S\)) of the copper in the alloys and the standard thermodynamic functions of formation and standard entropies of the ternary compounds.