In-situ observation of surface modification induced by highly charged ion bombardment

Nanoscale dots created on the surface of a highly oriented pyrolitic graphite sample by individual highly charged xenon projectile ions were observed using an in-situ scanning tunneling microscope. This is the first time that such features have been created and imaged without exposure to air. The dots vary in size with the charge state of the ion, up to a diameter of 6.6 nm for Xe44+. The results are discussed in terms of the energy density deposited in the near surface region.