[Zurück]

R. Ritter, Q. Shen, C. Teichert, R.A. Wilhelm, S. Facsko, R. Ginzel, J.R. Crespo López-Urrutia, F. Aumayr:
"Characterisation of nanostructures induced by slow highly charged ion bombardment of HOPG";
Poster: 25th International Conference on Atomic Collisions in Solids (ICACS-25), Kyoto University, Kyoto/Japan,; 23.10.2012; in: "Book of Abstracts, ICACS-25", (2012), S. 94.

Earlier studies, which have identified highly charged ion - induced defects on HOPG
surfaces as regions of enhanced friction [1] have been extended by measuring the
microscopic friction coefficient at the impact sites and the surrounding matrix by means of
lateral force microsopy. Additional investigations have been performed on samples
irradiated with ions in very high charge states (Xe40+ and Bi62+), and, for the first time,
defects have also been found employing the intermittent contact AFM mode (Figure 1),
where friction forces are basically eliminated from the measuring process (no pseudotopographic
contributions arising from friction). This is a strong indication that there is
indeed a true topographic modification (as found for other target surfaces; see [2] and refs
therein) if the impinging ions exceed a certain potential energy threshold. Furthermore,
defects have been imaged in the conductive AFM mode, where strong local changes
(imaging at atomic resolution) in the conductivity are apparent.
Figure