Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 59: Molecular Nanostructures

O 59.4: Vortrag

Donnerstag, 28. Februar 2008, 10:15–10:30, MA 041

Morphology of C58 layers deposited on HOPG — •Stefan-Sven Jester, Daniel Löffler, Patrick Weis, Artur Böttcher, and Manfred M. Kappes — Institut für Physikalische Chemie, Universität Karlsruhe, 76131 Karlsruhe, Germany

The low energy cluster beam deposition technique, LECBD, has been applied to grow monodisperse layers comprising of mass-selected carbon clusters, so called non-IPR fullerenes, Cn, 50<n<60 /1/. The morphology of the Cn layers deposited on HOPG has been studied by applying atomic force microscopy. The deposition has been performed at hyperthermal kinetic energies, E0, ranging from 1 - 49 eV. The initial capability of the Cn cages to adhere to the surface is governed by the lateral density of step edges which act as pinning and nucleation centers for migrating cages. Consequently the surface exhibits large areas of empty terraces and decorated step edges. The flat terraces become decorated by dendritic Cn islands only in later deposition stages. Both, the mean size of the 2D islands and the mean distance between nearest islands, d, scale with the size of the terraces. The topography of the islands depends sensitively on the primary kinetic energy, E0, and the surface temperature, TS. We explain these findings by considering the loss of the primary kinetic energy induced by molecular friction experienced by the Cn cages during their ballistic sliding/slipping path across the surface /2/.

[1] A. Böttcher, P. Weis, A. Bihlmeier, M.M. Kappes, PCCP 6 (2004) 5213 [2] a) W.D. Luedtke and U. Landman, Phys. Rev. Lett. 82 (1999) 3835, b) E. Molinari, M. Tomellini, Surf. Sci., 601 (2007) 1