Reassessment of the Mg–Ge binary system using CALPHAD supported by first-principles calculation

Abstract The Mg–Ge system is reassessed by means of the CALPHAD approach, supplemented with first-principles calculation. All of the experimental phase diagram and thermodynamic data available in the literature are critically reviewed and assessed by using thermodynamic models for the Gibbs energies of individual phases. Two models, the substitutional solution model and associate solution model, are employed to describe the Gibbs energy of the liquid phase. The enthalpy of formation for Mg2Ge is calculated by first-principles calculation with a desire to clarify the discrepancies in the literature data reported for the enthalpies of formation. Two sets of self-consistent thermodynamic parameters for the Mg–Ge system are finally obtained, with a substitutional solution model or associate solution model for the liquid phase. Some improvements have been made, compared with the previous assessments.