Thermodynamic assessment of EuBr 2 unary and LiBr–EuBr 2 and NaBr–EuBr 2 binary systems

Abstract

As a basis for the design and development of molten salt mixtures, thermodynamic calculations of the phase diagrams and thermodynamic properties were carried out on the EuBr 2 unary and LiBr–EuBr 2 and NaBr–EuBr 2 binary systems over a wide temperature and composition range, respectively. The Gibbs energy of EuBr 2 was evaluated using an independent polynomial to fit the experimental heat capacity, the thermodynamic parameters for each phase in the LiBr–EuBr 2 and NaBr–EuBr 2 systems were optimized by using available experimental information on phase diagrams. A regular substitutional solution model for the liquid phase and Neumann–Kopp rule for the stoichiometric compound LiEu 2Br 5 were adopted to reproduce the experimental data with reasonable excess Gibbs energy. Comparisons between the calculated phase diagrams and thermodynamic quantities show that all reliable experimental information is satisfactorily accounted for by the present thermodynamic description. Some thermodynamic properties were predicted to check the suitability of the present calculation.