Scanning Tunneling Microscopy of UV-Induced Gasification Reaction on Highly Oriented Pyrolytic Graphite

Abstract

Real-space observations of gasification reaction of graphite surface caused by UV irradiation were made using scanning tunneling microscopy (STM). The formation of etch pits on highly oriented pyrolytic graphite (HOPG) surface during gasification reaction was investigated. At the beginning of gasification reaction, domelike structures were formed. Further irradiation produced randomly distributed deep etch pits. When UV-irradiated samples were kept for 3 weeks at 50°C, the irregularly shaped deep etch pits stabilized and formed shallow etch pits one or two monolayers deep.