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Nanostrukturen und Grenzflächen Vortrag: Mi., 11:50–12:10 M-V11
Transmission surface x-ray diffraction studies of solid-liquid and liquidliquid
interfaces
Olaf Magnussen 1
1 Institut für Experimentelle und Angewandte Physik, Universität Kiel, Olshausenstr.
40, 24098 Kiel
Deeply buried interfaces between condensed phases, such as solid-liquid and liquidliquid
interfaces, are ubiquitous in nature as well as of great importance in many
technological processes, ranging from fuel cells to plating for microelectronics applications.
The high brilliance of modern synchrotron sources allows studies of the atomicscale
interface structure in-situ under realistic conditions. This will be illustrated
by studies of Au(111) and liquid Hg electrodes in aqueous electrolytes. Specifically,
grazing-incidence diffraction studies during homoexitaxial gold electrodeposition will
be presented that reveal a noticeable more compressed reconstructed Au surface layer
during Au deposition as compared to Au-free electrolyte [1]. Contrary to the Au-free
case, the surface compression increases with decreasing potential in Au-containing solution.
Second, it will be shown by in-situ x-ray reflectivity measurements that liquid
Hg electrodes exhibit stratification into atomic layers at the interface to simple salt solutions
[2]. This surface layering is even more pronounced than that found in previous
studies at the liquid Hg / vapour interface [3].
[1] Ayad, J. Stettner, O.M. Magnussen, Phys. Rev. Lett. 94 (2005) 066106.
[2] O. M. Magnussen, B. M. Ocko, I. Sloutkin, J. Baumert, I. Kuzmenko, and M.
Deutsch, in preparation.
[3] O. M. Magnussen, B. M. Ocko, M. J. Regan, K. Penanen, P. S. Pershan, and M.
Deutsch, Phys.Rev.Lett. 74 (1995) 4444.