Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 58: Poster Session III (Solid/liquid interfaces; Metals; Semiconductors; Oxides and insulators)
O 58.32: Poster
Mittwoch, 28. März 2012, 18:15–21:45, Poster B
HREELS Investigation of Ethene Chemisorption on Cu(110) — •Emanuel Welsch, Olaf Skibbe, Jan Pischel, and Annemarie Pucci — Kirchhoff-Institut für Physik, Im Neuenheimer Feld 227, D-69120 Heidelberg
Nowadays, the adsorption of ethene has been studied extensively and is well understood on a large number of the many possible single crystal metal subtrates. However, the properties of the chemisorption systems C2H4 on Cu(110) and on roughened copper substrates have always been discussed controversially [1-3], comprising the questions of adsorption geometry and of the anomalous IRRAS intensity of the observed gas phase Raman active vibrational modes. Whilst the former has implications on the issue whether a certain mode is dipole allowed or not, the explanation of the latter demanded a new excitation mechanism. Such a mechanism, based on the creation of electron hole pairs, has been established for the case of roughened copper substrates [4].
In this work we present the results of recent HREELS measurements which clearly demonstrate that the abovementioned model cannot explain the activation of the Raman active modes in the case of C2H4/Cu(110). Furthermore the selection rules of impact scattering are applied in order to discuss the compatibility of the spectra with several of the possible adsorption geometries.
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[2] J. Kubota et al. Phys. Chem., 98:7653-7656, 1994.
[3] R. Raval. Surf. Sci., 331-333:1-10, 1995.
[4] A. Priebe et al. J. Phys. Chem. B, 110:1673-1679, 2006.