Scanning-tunneling-microscope investigation of a 215-MeV Ne-irradiated graphite surface

Surface structure on highly oriented pyrolithic graphite irradiated by low-dose 215-MeV Ne ions was investigated by scanning tunneling microscopy. Three types of surface features were found: ones produced by low-energy knocked-on C atoms (type I, ones produced by high-energy knocked-on C atoms emerging from the irradiated surface of the target (type II), and a defect attributed to knocked-on C atom with energy around the maximum of electronic stopping moving in a direction approximatively parallel to the irradiated surface (type III). In some instances, atomic resolution was achieved on the observed surface features. Structures, which can be ascribed to entering of the Ne ions themselves, were not found.