Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 7: Metal Substrates: Adsorption I
O 7.6: Vortrag
Montag, 26. März 2007, 12:30–12:45, H39
Adsorption of Molecules Studied by Collision-energy-resolved Electron Spectroscopy with He*(23S) Metastable Atoms: Benzenes, Acetonitrile, and Acetic Acid on the Ag(110) at 80K — •Andriy Borodin1,2, Naoki Kishimoto1, Koichi Ohno1, and Michael Reichling2 — 1Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan — 2Department of Physics, University Osnabrueck, Barbarastr. 7, 49076 Osnabrueck, Germany
The interaction between metastable atoms and surfaces can be utilized for electron spectroscopy on surfaces (MIES). This technique is characterized by an extremely high surface sensitivity. Such a technique applied to the gas phase is also widely known as the 2D-PIES method, which provides information on the collision energy dependence of the ionization cross section for interaction between the He*(23S) atom and a target. In the presented work we show results of the 2D-method applied to acetonitrile, acetic acid, and benzenes adsorbed on Ag(110).
A strong collision-energy dependence of the band intensities was found for acetonitrile. The C-N group is attractive towards He*(23S), especially in a multilayer film, while He*(23S)-interaction with CH3-group has a rather neutral character. The intermolecular interaction in adsorbed films was studied for the acetic acid. The acetic acid dimers were found to be formed even in a sub-monolayer film at 80 K. Moreover, the adsorption of C6H6, C6H5OH, and C6H5SH was investigated. Flat adsorption was detected by the collision-energy-resolved technique for films with thickness of about 0.5 ML and 2 ML.