Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 59: Poster Session III (Nanotribology; Polymeric biomolecular films; Organic electronics and photovoltaics, Covalent networks on surfaces; Phase transitions; Particles and clusters; Transparent conductive oxides)
O 59.17: Poster
Mittwoch, 16. März 2011, 17:30–21:00, P3
Thermally activated decay of size selected clusters on thin C60 films — •Stefanie Duffe1, Niklas Grönhagen1, Lukas Patryarcha1, Benedikt Sieben1, Chunrong Yin2, Bernd von Issendorff2, Michael Moseler2,3,4, and Heinz Hövel1 — 1TU Dortmund, Experimentelle Physik I — 2Universität Freiburg, Fakultät für Physik — 3Fraunhofer Institute for Mechanics of Materials IWM — 4Freiburg Material Research Center
Metal nanoparticles supported by thin films are important for molecular electronics, biotechnology and catalysis, among other fields. Here we demonstrate a mechanism for the penetration of thin films and other nanoscopic barriers which is different from mere diffusion. Mass selected clusters from Ag55+ to Ag923± 9+ were soft landed at 165 K on graphite (HOPG) and Au(111) covered with 1 and 2 monolayers (ML) C60. Imaging by STM at 77 and 5 K showed that the clusters have extremely narrow cluster height distributions at low temperature [1]. Using C60/HOPG or 2 ML C60/Au(111) the cluster heights are stable for more than 12 h at room temperature, whereas for 1 ML C60/Au(111) Ag309 ± 3 clusters decayed and penetrated the C60 film [2]. Atomistic calculations reveal a process by which the clusters decay atom by atom through 1 ML C60/Au(111). These results demonstrate that a metallic substrate exerts attractive forces on metallic nanoparticles which are separated from the substrate by a single monolayer of C60 molecules.
[1] S. Duffe et al., Eur. Phys. J. D 45, 401 (2007)
[2] S. Duffe et al., Nature Nanotechnology 5, 335 (2010)