Novel Mechanism for Diffusion of One-Dimensional Clusters:Pt/Pt(110)(1×2)

Abstract
We report on a novel diffusion mechanism for one-dimensional platinum clusters on the anisotropic Pt110(1×2) surface. The mechanism, which is revealed from atom-resolved, time-lapsed scanning tunneling microscopy movies, entails that the end atom of a cluster is promoted up to the next layer, migrates over the cluster, and drops down again, resulting in a cluster displacement by one lattice spacing. The activation barriers for the atom to ascend and descend the cluster edges are estimated to be 0.91 and 0.70 eV, respectively. The reported observations have already inspired theoretical calculations.