Thermodynamic analysis of the Pt–Sn system

A consistent thermodynamic description of the Pt–Sn system is generated using the Calphad method. Serious artifacts in a previous thermodynamic assessment of this system are pointed out. The thorough reassessment is based on all published original experimental data on phase equilibria and thermodynamic alloy properties, which have been critically evaluated. The associate solution model was used for the liquid phase with a strongly forming associate “PtSn” and the relevance for possible short-range order or cluster formation is discussed. The (Pt) solution phase is modeled as substitutional solution and the intermediate phases Pt3Sn, PtSn, Pt2Sn3, PtSn2, PtSn4 are considered as stoichiometric phases. The assignment of reasonable values of thermodynamic parameters is further demonstrated by the consideration of absolute entropies and entropies of fusion of all the intermetallic compounds.