Regensburg 2002 – wissenschaftliches Programm
SYCO 4.7: Poster
Donnerstag, 14. März 2002, 18:45–19:30, H 36 Foyer
Dynamic force microscopy investigations on thin Au55 monolayers — •Georgeta Radu and Uwe Hartmann — Fachrichtung Experimentalphysik, Universität des Saarlandes, 66123 Saarbrücken
Thin layers of ligand-stabilized Au55 clusters on mica and HOPG substrates were imaged by noncontact atomic force microscopy (NC-AFM) in ultrahigh vacuum (UHV). The clusters were dissolved in dichlormethane (CH2Cl2) and deposited onto freshly prepared substrates by spin coating. For a sufficiently low cluster concentration in the solution the deposit consists of areas with a layer of single cluster height alternating with areas showing the bare substrate. Room-temperature NC-AFM imaging confirmed the strong interaction between Au55 and mica which was previously found by variable-temperature needle-sensor investigations. In the case of a HOPG substrate, the interaction was found to be weaker, again in accordance to previous needle-sensor investigations. Imaging of single clusters was possible by NC-AFM on HOPG and mica substrates. Dynamic force spectroscopy as well as dissipation analysis were performed in comparation for the two systems.