Thermodynamic reassessment of the neodymium–gold binary system

Phase relationships in Nd–Au binary system have been thermodynamically assessed by means of the CALPHAD technique through Thermo–Calc software package based on the experiment information of phase equilibria and thermodynamic properties from the published literature data. The excess Gibbs energy functions of the solution phases including liquid, fcc_A1, bcc_A2, and dhcp were formulated with Redlich–Kister polynomial functions. The two–sublattice energy model was employed to describe the Nd₁₄Au₅₁ phase which exhibits a homogeneity range. The intermetallic compounds Nd₂Au, NdAu, Nd₃Au₄, Nd₁₇Au₃₆, and NdAu₆ were treated as stoichiometric phases. A set of self-consistent thermodynamic parameters formulating the Gibbs energy of various phases in the Nd–Au binary system were then obtained. A much better agreement was achieved between the calculated results and the reported experimental data. - Highlights: • The Nd–Au has been re-assessed using the latest experimental results. • The intermetallic compound Nd₁₄Au₅₁ was treated by a two–sublattice model. • The errors of related modelling presented in previous articles have been modified. • A self–consistent thermodynamic description of the Nd–Au system was obtained.