Direct Calculation of Interfacial Free Energy Using Molecular Simulation

Saturday, July 28, 2007 - 10:00am - 10:20am
EE/CS 3-180
Brian Laird (University of Kansas)
The interfacial free energy is the work required to reversibly form a unit area of interface between two materials and is a principal quantity governing crystal growth kinetics and morphology, nucleation and wetting phenomena. In this talk I will review our recent work on the direct calculation of the interfacial free energy for a number of model systems including crystal/fluid, wall-fluid and wall-crystal systems. For the crystal-melt interface, our method of cleaving walls, based on thermodynamic integration [Phys. Rev. Lett, 85, 4751 (2000)], is of sufficient precision to resolve the often small anisotropy in the interfacial free energy, which is crucial in determining the kinetics and morpholgy of dendritic growth. Our calculations are motivated by the enormous difficulty in obtaining precise interfacial free energies by experiment. We report values of the crystal-melt interfacial free energy for the hard-sphere and Lennard-Jones systems, as well as recent results on the series of inverse-power potentials. In addition, recent work extending the method to wall-fluid and wall-crystal systems is discussed and applied to a recent controversy regarding surface-induced prefreezing in hard-spheres.