Structure of the Lennard-Jones (100) crystal-liquid interface

Abstract

The crystal-liquid interface, as computed by molecular dynamics at the triple point, is examined in the light of current models. Thermodynamic profiles of the density, potential energy and stress shows the interface is broad, extending over several atomic diameters. The density, configurational entropy, and diffusivity in the parallel planes, all change gradually through the interfacial region. In contrast to theoretical models, the density decrease arises primarily from an enhanced interlayer spacing, mainly on the crystal side, rather than from a depletion of the occupancy through vacancies. Trajectory plots obtained by computer graphics show the intermediate layers to be heterogeneous reflecting mountainous regions of registration extending into the liquid.