Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 29: Nanoengineered Thin Films II
DS 29.1: Vortrag
Donnerstag, 26. März 2009, 11:15–11:30, GER 37
Geometric properties and thermal stability of size selected Ag clusters on C60 films — •Stefanie Duffe1, Lukas Patryarcha1, Ben Wortmann1, Bernd von Issendorff2, Michael Moseler2, 3, 4, and Heinz Hövel1 — 1TU Dortmund, Experimentelle Physik I, 44221 Dortmund, Germany — 2Universität Freiburg, Fakultät für Physik, 79104 Freiburg, Germany — 3Fraunhofer Institut für Werkstoffmechanik, 79108 Freiburg, Germany — 4Freiburger Materialforschungszentrum, 79104 Freiburg, Germany
Mass selected clusters from Ag55+ to Ag923± 9+ were soft landed at 165 K on C60/HOPG and C60/Au(111) and imaged with STM at 77 and 5 K. We observed extremely narrow cluster height distributions. The cluster heights are in agreement with calculated heights for spherical clusters. We studied the thermally activated decay of the deposited clusters. Using C60/HOPG or 2 ML C60/Au(111) the cluster heights are stable for more than 12 h at RT. For 1 ML C60/Au(111) the clusters decay atom by atom, which is revealed by atomistic calculations [1, 2]. For Ag309± 3 and Ag923± 9, we used scanning tunnelling spectroscopy at 5 K and measured identical spectral features for individual clusters with the same selected size. The spectra can be classified in different groups showing energetic shifts of the peaks due to different shapes of the STM tip. For this reason, we measured spectra of C60 molecules as reference. Besides, we observed for 2 ML C60/HOPG three different orientations of the C60 molecules in STM images measured at 5 K. In contrast, the first ML C60 molecules/HOPG show only one orientation.
[1] S. Duffe et al., EPJD 45, 3 (2007), [2] S. Duffe et al., submitted