Direct calculation of the crystal-melt interfacial free energies for continuous potentials: Application to the Lennard-Jones system

TL;DR

This paper extends a molecular-dynamics simulation method to continuous potentials to accurately calculate the crystal-melt interfacial free energies for a Lennard-Jones system, revealing anisotropy and comparing with prior models and materials.

Contribution

It introduces an extension of the cleaving wall method to continuous potentials for precise interfacial free energy calculations.

Findings

Calculated interfacial free energies for Lennard-Jones system at various orientations and temperatures.

Confirmed anisotropy: γ_111 < γ_110 < γ_100 across studied temperatures.

Results are consistent with previous studies but with higher precision.

Abstract

Extending to continuous potentials a cleaving wall molecular-dynamics simulation method recently developed for the hard-sphere system [Phys.Rev.Lett 85, 4751 (2000)], we calculate the crystal-melt interfacial free energies, $\gamma$, for a Lennard-Jones system as functions of both crystal orientation and temperature. At the triple point, T* = 0.617, the results are consistent with an earlier cleaving potential calculation by Broughton and Gilmer [J. Chem. Phys. {\bf 84}, 5759 (1986)], however, the greater precision of the current calculation allows us to accurately determine the anisotropy of $\gamma$. From our data we find that, at all temperatures studied, $\gamma_{111} < \gamma_{110} < \gamma_{100}$. Comparison is made to the results from our previous hard-sphere calculation and to recent results for Ni by Asta, Hoyt and Karma [Phys. Rev. B, 66 100101(R) (2002)].