Effect of 305-MeV krypton ions on the surface of highly oriented pyrolytic graphite

The surface of highly oriented pyrolytic graphite (HOPG) irradiated by 305-MeV krypton ions was studied in a scanning tunneling microscope. It was found that inelastic energy losses of the krypton ions do not significantly affect the sputtering of carbon from the surface of crystalline HOPG grains. Similarly to the case of metals, preferential sputtering takes place in the grain boundaries. The inhomogeneous sputtering of polycrystalline conductors has to be taken into account in interpreting experimental data on the sputtering of such targets by high-energy heavy ions in the range of inelastic energy losses. The results can be also implemented in the technology of ion implantation into deep layers of solids.