A thermodynamic description of the KBr–EuBr2 system

• CALPHAD method was used to derive thermodynamic parameters of the system.
• Heat capacities of K2EuBr4 and KEu2Br5 were fitted to literature data.
• Phase diagram of KBr–EuBr2 was calculated.
• More investigations were necessary to check the stability of the compounds.

Critical thermodynamic description on KBr–EuBr2 system was carried out by CALPHAD method. The thermodynamic parameters of the pure KBr and EuBr2 compounds were taken from the SGTE recommended database and the authors’ previous assessment, respectively. A two-sublattice ionic solution model for the liquid, denoted as (K+)P(K+)P:(Br−, EuBr4-2, EuBr2)Q, was employed to represent phase diagram and enthalpy of mixing data. To reach a self-consistent thermodynamic description for the constituent phases in the system, the experimental heat capacity data of the intermediate compounds K2EuBr4 and KEu2Br5 were evaluated.