First-principles calculation aided thermodynamic modeling of the Mo–Re system

A thermodynamic description of the Mo–Re system is successfully developed with the aid of first-principles calculation. The intermetallic phases, σ and χ, in the Mo–Re system were described by sublattice models of Re10(Mo,Re)4(Mo,Re)16 and (Mo,Re)10(Mo,Re)24Re24, respectively, in accordance with their crystal structures and elemental site occupation preferences. The zero-K enthalpies of formation of the end-member compounds defined by these two models were calculated by first-principles method. The first-principles calculated values together with the critically reviewed experimental data from literature were then used to develop a thermodynamic description of the Mo–Re system using the Calphad approach. Calculated results are in good agreement with experimental data. Differences between this modeling and two other recently reported thermodynamic models of the Mo–Re system are discussed.