Exchange mechanism for adatom diffusion on metal fcc(100) surfaces

摘要

We study the self-diffusion of adatoms on metal fcc(100) surfaces by molecular dynamics with Pt and Ag as examples. The metals are modeled by surface embedded-atom potentials. Besides the well-known exchange diffusion mechanism, another one that appears as the diffusion of an ad-dimer is also observed, and it can be explained by the "concerted motion" model owing to the strong bonds formed in the transition state. The important point is that this mechanism could appear frequently even at room temperature and makes adatoms more movable on fcc(100) surfaces. [S0163-1829(98)01423-4]. [References: 18]