Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 14: Poster session I (Adsorption, Epitaxy and growth, Phase transitions, Surface reactions, Organic films, Electronic structure, Methods) (sponsored by Omicron Nanotechnology GmbH)

O 14.8: Poster

Montag, 27. März 2006, 18:00–21:00, P2

Interaction of oxygen and hydrogen with a Pd(110) surface — •Tobias Pertram, Marko Kralj, Aleksander Krupski, Conrad Becker, and Klaus Wandelt — Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, D-53115 Bonn, Germany

The clean Pd(110) surface has a tendency towards reconstruction and even small quantities of adsorbed atoms can trigger the process of surface restructuring. In the case of room temperature hydrogen adsorption it is understood that the (1×2) missing-row reconstruction is stabilized by the creation of (111) micro facets, which provide the most stable adsorption sites for hydrogen atoms [1].
In our study we perform in situ scanning tunneling microscopy (STM) and observe the surface restructuring induced by the adsorption of hydrogen or oxygen on clean Pd(110). We are interested in the adsorption of small amounts of the respective adsorbate and study the importance of large terraces and step edges in the initial stages of restructuring. The results indicate that the steps oriented in the [001] direction are of particular significance for the coherent surface restructuring. A statistical analysis shows that the reconstructed surface area for small exposures increases exponentially with exposure. This suggests that equal amounts of adsorbate do not lead to equal increments of restructured area but the accumulated dose plays a crucial role in the kinetics.

[1] V. Ledentu, W. Dong, P. Sautet, G. Kresse, J. Hafner, Phys. Rev. B 57 (1998) 12482.