Thermodynamic optimization of the Cu–Nd system

The thermodynamic constraints to eliminate artificial phase relations were introduced with the Cu–Nd system as an example. The enthalpies of formation of the compounds Cu6Nd, Cu5Nd, Cu2Nd and αCuNd are calculated using density functional theory. Taking into account all the experimental data and the first-principles calculated enthalpies of formation of these compounds, the thermodynamic optimization of the Cu–Nd system was performed under the proposed thermodynamic constraints. It is demonstrated that the thermodynamic constraints are critical to obtain a set of thermodynamic parameters for the Cu–Nd system, which can avoid the appearance of all the artificial phase relations.

Research highlights▶ The enthalpies of formation of the compounds Cu6Nd, Cu5Nd, Cu2Nd and αCuNd were calculated using DFT. ▶ The thermodynamic constraints to eliminate the artificial phase relations were imposed during the thermodynamic optimization procedure. ▶ The Cu–Nd system was optimized under the thermodynamic constraints.