Thermodynamic evaluation and modeling of the CeF3-LaF3-LiF-NaF system

The thermodynamic properties of the LiF-NaF-CeF 3 -LaF 3 pseudo-quaternary system have been evaluated, and models for the relevant phases have been revised or newly developed. The solid solubility of NaF in LaF 3 and CeF 3 was described in the model based on reported phase-equilibria observations and results from density functional theory calculations. The Gibbs energy functions for the NaCeF 4 and NaLaF 4 phases have been updated with recently reported thermochemical measurements. The Gibbs energy functions and model relations for the LiF-NaF-LaF 3 and LiF-NaF-CeF 3 pseudo-ternary systems were successfully optimized based on thermochemical properties and phase equilibria observations. • Incorporated new thermochemical data for the NaLaF 4 and NaCeF 4 ternary compounds into the CALPHAD model. • Remodeled LaF 3 -LiF-NaF and CeF 3 -LiF-NaF pseudo-ternary systems with both phase equilibria and thermochemical data. • The work considered how the solid solubility between the NaLaF 4 and NaCeF 4 affect the liquidus projection of the CeF 3 -LaF 3 -NaF pseudo-ternary system. • Models have been included in the MSD-TC for molten salt reactor design.