Tension and Stiffness of the Hard Sphere Crystal-Fluid Interface

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 0.66kBT/σ² with a small anisotropy of about 0.025kBT and stiffnesses with, e.g., 0.53kBT/σ² for the (001) orientation and 1.03kBT/σ² for the (111) orientation. Here kBT is denoting the thermal energy and σ the hard-sphere diameter. We compare our results with existing experimental findings.