Scanning tunneling microscopy observation of local damages induced on graphite surface by ion implantation

This paper presents a STM study relative to the first step in the modification of a graphite surface on which argon ions of 50 keV kinetic energy have been implanted. Very low ion doses (∼ 1011 ions cm-2) were used in order to isolate single-ion impacts and to characterize the damages due to one ion impact on the surface. Implantations were performed on highly oriented pyrolytic graphite (HOPG) whose lamellar structure allows easy cleavage and preparation of large flat terraces extending over hundreds of nanometers. Such flat standard surfaces are well suited to study the effects of ion bombardment