Thermodynamic assessments of the Pu–Zn and La–Pu systems

Highlights: • The Pu–Zn and La–Pu binary systems have been assessed by using the CALPHAD method for the first time. • The intermetallic compounds which have homogeneity range were described by the two-sublattice model. • The parameters of the Pu–Zn and La–Pu binary systems can serve as a part of the thermodynamic database for nuclear materials. • The calculated results are in good agreement with the experimental data. - Abstract: The thermodynamic description of the Pu–Zn and La–Pu systems were obtained using the CALPHAD (Calculation of Phase Diagrams) method on the basis of experimental information for phase equilibria and thermodynamic properties. The Gibbs free energies of the liquid, (εPu), (δ′Pu), (δPu), (γLa) and (βLa) phases were described by the subregular solution model. Seven intermetallic compounds (PuZn₂, Pu₁₃Zn₅₈, Pu₃Zn₂₂, Pu₂Zn₁₇, κ, κ′, and λ) were modeled by the sublattice model. A reasonable agreement between the present calculated results and experimental data has been achieved with a set of optimized parameters