V. A. Krashaninin, N. E. Dubinin
ABSTRACT
Concentration dependencies of the Helmholtz free energy of mixing are calculated for liquid Li–Rb, K–Rb and Li–Na alloys at different temperatures by using the variational method of the thermodynamic perturbation theory and the first-principle pseudopotential with the true wave functions instead of the pseudo-wave ones employed for calculation the screening potential. An excellent agreement with the experimental phase diagram is achieved in description of the phase separation in Li–Rb alloy. The ideal mixing in K–Rb alloy and the phase-separation tendency in Li–Na alloy are obtained only at temperatures that are higher than ones observed experimentally.
KEYWORDS: variational method, first-principle pseudopotential, liquid binary metal alloy, Helmholtz free energy of mixing.