Possible diamond-like nanoscale structures induced by slow highly-charged ions on graphite (HOPG)

Abstract

The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highlyoriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosize areas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

Comparative study of irradiation effects in graphite and graphene induced by swift heavy ions and highly charged ions

“…In many solids, hillocks are induced by SHI at the surface with a radius that depends on the electronic energy loss [4][5][6][7][8]. Similar surface nanostructures were also detected on HCI impacted materials [9][10][11][12]. The similarity among the nanostructures indicates that a common mechanism related to the energy transfer process is involved in both irradiation types.…”

“…1a, 1b and 1c. During the irradiation of 479 MeV Kr ions on HOPG, a new peak denoted as D peak (~1338 cm -1 ) appears in addition to the original G peak (~1582 cm -1 ) when the fluence is 5×10 12 ions/cm 2 or higher (insert of Fig. 1a).…”

Surface nanostructures by single highly charged ions

“…As an interesting application it was demonstrated that the defects induced by HCI on HOPG can be transformed by subsequent irradiation with electrons (from the STM tip) or photons (Cd-Te laser) to sp 3 graphite, i.e. to nanoscaled diamond structures [46][47][48]. Recently, these modifications could be found also in simulations of the impact of highly charged Ar ions on graphite using time-dependent density functional theory combined with MD [49].…”