Thermodynamic assessment of Au–La and Au–Er binary systems

Abstract Phase relationships in Au–La and Au–Er binary systems have been thermodynamically assessed by using the CALPHAD technique. The existing thermodynamic descriptions of the systems were improved by incorporating the ab initio calculated enthalpies of formation of the intermetallic compounds, except for the Au 51 La 14 and Au 10 Er 7 phases. All the binary intermetallic compounds were treated as stoichiometric phases, while the solution phases, including liquid, fcc, bcc, and dhcp, were treated as substitutional solution phases and the excess Gibbs energies were formulated with Redlich–Kister polynomial function. As a result, two self-consist thermodynamic data sets for describing the Au–La and Au–Er binary systems were obtained.