Free-energy calculations and the melting point of Al

Abstract

The temperature dependence of the Gibbs free energies of crystalline and liquid aluminum have been calculated using the embedded-atom method with molecular dynamics. The resulting thermodynamic melting point ${\mathit{T}}_{\mathit{m}}$ is 800 K, about 130 K below the experimental value. From the simulation, the free energy of the crystalline phase was obtained by thermodynamic integration methods, while the liquid free energy was calculated by choosing the ideal gas as the reference system. Crystal-liquid interface simulations at zero pressure and several temperatures above and below ${\mathit{T}}_{\mathit{m}}$ have been carried out. Melting and freezing processes were observed.