Thermodynamic calculation of the GdCl3–ACl (A=Na,K,Rb,Cs) phase diagrams based on experimental data

An optimization of the binary GdCl3–ACl (A=Na,K,Rb,Cs) systems has been carried out using the CALPHAD technique. The new modified quasi-chemical model in the pair-approximation for short-range ordering was used to describe the Gibbs energies of the liquid phase in these systems. Based on the measured phase equilibrium data and experimental thermochemical properties, the GdCl3–ACl phase diagrams were optimized and calculated. A set of thermodynamic functions has been optimized based on an interactive computer-assisted analysis. The calculations based on the obtained descriptions show good agreement with experimental phase diagrams and thermodynamic values.