Self-diffusion on the Lennard-Jones fcc(111) surface: Effects of temperature on dynamical corrections

Abstract

Surface self-diffusion constants have been calculated for the single component Lennard-Jones fcc(111) system using the dynamical corrections formalism for transition state theory (TST). At high temperatures, these results are found to be in agreement with previous molecular dynamics calculations. Over the extended temperature range in which this method is valid, deviations from Arrhenius behavior are observed. At lower temperatures, a noticeable contribution to the diffusion constant stems from trajectories in which the adatom recrosses the TST boundary, often due to a direction-reversing collision with the substrate atom on the far side of the binding site. This produces a dip in the dynamical correction factor centered around a reduced temperature of T=0.038. At higher temperatures, the expected multiple-jump effects are observed.