Tension and stiffness of the hard sphere crystal-fluid interface

TL;DR

This study combines density functional theory and Monte Carlo simulations to accurately determine the orientation-dependent interfacial tension and stiffness of the hard-sphere crystal-fluid interface, aligning well with experimental data.

Contribution

It provides the first quantitative agreement between microscopic density functional theory and simulations for the anisotropic interfacial properties of hard-sphere systems.

Findings

Interfacial tension of 0.66 kT/σ² with small anisotropy

Stiffness values of 0.53 kT/σ² for (001) and 1.03 kT/σ² for (111) orientations

Good agreement with experimental measurements

Abstract

A combination of fundamental measure density functional theory and Monte Carlo computer simulation is used to determine the orientation-resolved interfacial tension and stiffness for the equilibrium hard-sphere crystal-fluid interface. Microscopic density functional theory is in quantitative agreement with simulations and predicts a tension of 0.66 kT/\sigma^2 with a small anisotropy of about 0.025 kT and stiffnesses with e.g. 0.53 kT/\sigma^2 for the (001) orientation and 1.03 kT/\sigma^2 for the (111) orientation. Here kT is denoting the thermal energy and \sigma the hard sphere diameter. We compare our results with existing experimental findings.