The crystal-liquid interface of a body-centered-cubic-forming substance: Computer simulations of the r-6 potential

Abstract

The interfaces between a bcc crystal and its melt are studied by molecular dynamics simulation. Three distinct crystal/melt interfaces, (100), (111), and (110) are studied. For all interfaces the variation with z, the coordinate perpendicular to the interfacial plane, of the single particle density (averaged over the directions perpendicular to z) and the diffusion constant are measured. Although the 10-90 widths of the density peak-height profiles differ significantly among the three interfaces (6, 9, and 7 molecular diameters, respectively), the corresponding 10-90 widths of the diffusion constant profiles are nearly identical with a common value of about four molecular diameters. This leads to the conclusion that the differences in apparent structural width are due primarily to geometric considerations and not to differences in average local molecular environments. © 1989 American Institute of Physics.