Scanning-Tunneling-Microscope Observation of Surface Diffusion on an Atomic Scale: Au on Au(111)

Abstract

Time-lapse topography has been done with a scanning tunneling microscope on a clean, annealed Au(111) surface showing the effects of surface diffusion of Au atoms at room temperature. Within several minutes, features such as marks made by a gentle touch of the tunnel tip are seen to change as a result of the diffusion of Au atoms over the surface. The diffusion does not depend on the magnitude or sign of the tunneling current and voltage parameters. These experiments demonstrate the unique ability of the scanning tunneling microscope to obtain directly information about surface diffusion on an atomic scale.