Thermodynamic assessments of the Au–Th and As–U systems

The thermodynamic assessments of the Au–Th and As–U binary systems were carried out using the CALPHAD (CALculation of PHAse Diagram) method based on experimental data for phase equilibria and thermodynamic properties. The Gibbs free energies of the liquid, bcc, fcc, rhombohedral, (αU) and (βU) phases were described by the subregular solution model, and those of the intermetallic compounds (Au51Th14, Au2Th, Au4Th3, AuTh, Au2Th3 AuTh2, AsU, As4U3 and As2U) were described by the two-sublattice model. A set of thermodynamic parameters leading to reasonable agreement between the present calculated results and experimental data have been obtained.