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O: Oberflächenphysik

O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)

O 14.10: Poster

Montag, 8. März 2004, 18:00–21:00, Bereich C

Influence of Surface Roughness on the Wetting Behaviour of Liquid Helium on Alkali Metal Surfaces — •Martin Zech, Armin Fubel, Jürgen Klier, and Paul Leiderer — University of Konstanz, Department of Physics, 78457 Konstanz, Germany

For many times wetting transitions have been observed for helium and hydrogen on certain alkali metal surfaces. However, there exist discrepancies in the measured contact angles and accompanying hysteresis, in the movement of the helium contact lines, and sometimes even in the wetting temperature. Surface roughness is expected to have a significant influence on the wetting properties, but the working mechanism is not clearly understood yet. For this reason we have developed a special low temperature setup. This allows simultaneously an in situ evaporation of the alkali metals, an investigation of the substrate surface using a scanning tunnelling microscope (STM), and an investigation of the wetting behaviour of liquid helium on those surfaces. A coherence between different surface nanostructuring and emerging wetting phenomena is aimed to be obtained.