Elastic field of a surface step: Atomistic simulations and anisotropic elastic theory.

Abstract

Atomistic computer simulations and anisotropic elastic theory are employed to determine the elastic fields of surface steps and vicinal surfaces. The displacement field of and interaction energies between {l_angle}100{r_angle} steps on a {l_brace}001{r_brace} surface of Ni and Au are determined using atomistic simulations and embedded-atom method potentials. The step-step interaction energy found from the simulations is consistent with a surface line force dipole elastic model of a step. We derive an anisotropic form for the elastic field associated with a surface line force dipole using a two-dimensional surface Green tensor for a cubic elastic half-space within the Stroh formalism. Both the displacement fields and step-step interaction energy predicted by the theory are shown to be in excellent agreement with the simulations. The symmetry of the step displacement field is used to determine analytically the relative values of the components of the surface force dipole vector. {copyright} {ital 1996 The American Physical Society.}