Thermodynamic modeling of the Ga-Gd binary system

Abstract The Ga-Gd binary system was optimized using the experimental data available on the phase diagram and the thermodynamic functions according to the CALPHAD approach. The Ga - G d binary system contains five intermetallic compounds: Ga 6 G d , Ga 2 G d , GaGd , Ga 2 Gd 3 and Ga 3 Gd 5 . These phases are stoichiometric, with the exception of the Ga 2 G d compound which has a wide range of homogeneity. The Association solution model was used to describe the Gibbs excess energy term for the liquid phase and the solid solution. The Ga-Gd binary system was examined using the description of the linear dependence of temperature (Redlich-Kister Model). Our calculations are in good agreement with the data of the phase diagram and the experimental thermodynamic values available in the literature. The optimization procedure allowed us to calculate for the first time the phase equilibrium and the thermodynamic properties of the liquid phase and the intermetallic compounds.