Thermodynamic Characterization of the Congruently Melting Cs3CeCl6 Compound

The thermodynamic properties of the congruently melting Cs3CeCl6 compound, which is known to exist in the CeCl3−CsCl system, were studied by differential scanning calorimetry and Knudsen effusion mass spectrometry. The heat capacity of solid and liquid Cs3CeCl6 was measured as a function of temperature in the range (300 to 1100) K. The thermodynamic activities of CsCl and CeCl3 were determined in the two-phase field {Cs3CeCl6(s) + liquid}. These data were used to calculate the whole set of thermodynamic functions for the solid and liquid compound as well as the temperature variation of the Gibbs free energy and enthalpy of compound formation according to the reaction CeCl3(s,l) + 3CsCl(s,l) = Cs3CeCl6(s,l).