The Gibbs free energies and entropies of formation of pseodobinary compounds Cs3LnCl6(s) and CsLn2Cl7(s), CsCl-LnCl3 (Ln = Ce, Pr, Nd), from the constituent metal halides have been determined by Knudsen effusion mass spectrometry. These data have been compared with the thermodynamic properties of the solid and liquid phases of the pseudobinary systems, obtained by different methods.
The compatibility of the results obtained in this work for the pseudobinary compounds and other literature data have been assesed by optimisation program BINGSS of H. L. Lukas.
The phase diagrams, thermodynamic functions of mixing for systems studied have been obtained in the optimisation procedure. The calculated and measured values of Gibbs free energies of formation of Cs3LnCl6(s) and CsLn2Cl7(s) have been analized. The compatibility between phase diagram and thermodynamic functions of formation for pseudobinary compounds determined in the present study was stated by the modelling procedure.