Thermodynamic Modeling of the Li-H and Ca-H Systems

The phase diagram and thermodynamic properties of the Li-H and Ca-H systems in the literature are critically reviewed. The Gibbs energy functions of individual phases in these two systems are modeled by the CALPHAD approach. The associate solution model and substitutional model are employed to represent the thermodynamic properties of the liquid phase in the Li-H and Ca-H systems, respectively. The available experimental data are well reproduced by the present modeling. With the obtained Gibbs energy functions, the phase relationships in the Li-H and Ca-H systems at high pressures are also predicted.