Thermodynamic Assessment of Ag-Cu-In

The Ag–Cu–In thermodynamic material system is of interest for brazing alloys and chalcopyrite thin-film photovoltaics. To advance these applications, Ag–Cu–In was assessed and a Calphad model was developed. Binary Ag–Cu and Cu–In parameters were taken from previous assessments, while Ag–In was re-assessed. Structure-based models were employed for β-bcc(A2)-Ag₃In, γ-Ag₉In₄, and AgIn₂ to obtain good fit to enthalpy, phase boundary, and invariant reaction data for Ag–In. Ternary Ag–Cu–In parameters were optimized to achieve excellent fit to activity, enthalpy, and extensive phase equilibrium data. Relative to the previous Ag–Cu–In assessment, fit was improved while fewer parameters were used.