Molecular dynamics simulation of adsorption of Ag particles on a graphite substrate

We have performed for the first time a molecular dynamics simulation of the adsorption of gas-phase Ag particles on a graphite substrate to provide an insight into the results of a comprehensive STM-based experiment on this system. Both pair-wise and many-body interatomic potentials have been employed, and a Morse-type Ag–C potential was specifically constructed to describe the interactions at the interface. Our simulation has successfully reproduced a significant portion of the experimental findings. We have also observed the intercalation of silver in graphite.

Modelling the adsorption and imaging of C60 molecules on a graphite substrate

The adsorption of a C60 monolayer on a graphite substrate was modelled via molecular dynamics simulation covering a significant period of 160 picoseconds. The final configuration of C60s agrees closely with that observed in a scanning tunnelling microscopy (STM) experiment. Clusters of adsorbed molecules were then selected and their STM-like images were computed via the Keldysh Green function method.

Numerical modelling of adsorption of metallic particles on graphite substrate via molecular dynamics simulation

A computer-based numerical modelling of the adsorption process of gas phase metallic particles on the surface of a graphite substrate has been performed via the application of molecular dynamics simulation method. The simulation relates to an extensive STM-based experiment performed in this field, and reproduces part of the experimental results. Both two-body and many-body inter-atomic potentials have been employed. A Morse-type potential describing the metal-carbon interactions at the interface was specifically formulated for this modelling. Intercalation of silver in graphite has been observed as well as the correct alignments of monomers, dimers and two-dimensional islands on the surface. PACS numbers: 02.60.Cb, 07.05.Tp, 68.55.-a, 81.05.Tp

Observation of C60 film formation on a highly oriented pyrolitic graphite substrate via scanning tunnelling microscopy

We have investigated the early stages in the adsorption process of C60 molecules on a highly oriented pyrolitic graphite (HOPG) substrate. C60 powder was thermally evaporated in UHV of 10−8 Pa conditions onto a freshly cleaved HOPG surface. We did not observe individual fullerenes on the substrate for the case of short deposition times and low evaporation rates. However, small islands of C60 molecules with an fcc structure could be observed when the deposition rate was about 0.2 nm/min and the total thickness was above 1 nm. The islands did not grow in the vicinity of the HOPG steps. The typical lateral dimensions of these islands were of the order of a few hundred square nanometers, having thickness of up to five monolayers. We modified the shapes and positions of these islands by the STM tip, using a small (less than 1 V) bias voltage.