Thermodynamic assessment of the calcium-germanium system

Thermodynamic modeling of the Ca-Ge system was carried out by means of the CALPHAD (calculation of phase diagrams) method and new experimental phase diagram data. The liquid phase and the intermetallic compounds Ca2Ge, Ca5Ge3, Ca7Ge6 (new compound), CaGe and CaGe2 are taken into consideration in this optimization. The substitutional solution model was used to describe the liquid phase. The five compounds were treated as stoichiometric phases. A consistent set of thermodynamic parameters has been obtained. The optimized phase diagram and thermodynamic properties are presented and compared with other calculated and experimental data obtained from literature.