Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 36: Postersitzung (Elektronische Struktur, Grenzfl
äche fest-flüssig, Halbleiteroberfl
ächen und -grenzfl
ächen, Nanostrukturen, Oberfl
ächenreaktionen, Teilchen und Cluster, Struktur und Dynamik reiner Oberfl
ächen)
O 36.60: Poster
Montag, 7. März 2005, 15:00–18:00, Poster TU F
Direct and indirect manipulation of small water clusters on Ag(111) — •H. Gawronski1, K. Morgenstern2, M. Mehlhorn1, and K.-H. Rieder1 — 1Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, 14195 Berlin — 2Universität Hannover, Institut für Festkörperphysik, Appelstr. 2, 30167 Hannover
Scanning tunneling microscopy (STM), ineleastic tunneling spectroscopy (IETS), and electron induced manipulation at low temperature are used to investigate the dynamics of small D2O clusters of 6 to 12 molecules formed by deposition of water at 25K. To get information about the formational changes of the clusters, their excitation energy, and their vibrational modes we use electron induced manipulation at a temperature of 5K. Formational changes of the D2O clusters are induced by injecting electrons directly into the cluster with an energy of 180meV. The energies needed for indirect excitation of a cluster at manipulation distances of a few Ångstrom from the cluster are about a factor 1.5 to 2 higher than those for direct excitation. IETS allows us to identify vibrational modes, namely the frustrated translations and rotation, of D2O clusters on the Ag(111) surface. Furthermore the gap of the water molecule is visible in the spectra. The results are related to previous IETS and EELS measurements for H2O bilayers and clusters on the (111) faces of Au, Ag, and Cu.