Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 72: Solid-Liquid Interfaces: Reactions and Electrochemistry
O 72.5: Poster
Mittwoch, 9. März 2016, 18:15–20:30, Poster A
In situ Surface X-ray Diffraction Study of Ultrathin Epitaxial Co Films on Au(111)/H-Si(111) in Transmission Geometry — •Jonathan Laufer1, Finn Reikowski1, Tim Wiegman1, Fouad Maroun2, Philippe Allongue2, Jakub Drnec3, Jochim Stettner1, and Olaf M. Magnussen1 — 1IEAP, CAU Kiel, Germany — 2Ecole Polytechnique, CNRS, Palaiseau, France — 3ESRF, Grenoble, France
Gracing incidence diffraction in reflection geometry belongs to the standard repertoire for the in situ characterization of single crystal surfaces and adsorbate structures. Although being commonly used for measurements of crystal truncation rods, mapping in-plane structures proves to be tedious with this method. Here we present surface diffraction studies in transmission geometry, in which a large portion of the in-plane structure can be seen on a single detector frame. To flatten the curvature of the Ewald sphere, high energies in the range 25 keV to 70 keV were used. This means that the out-of-plane wavevector transfer changes only slightly over the range of reciprocal space covered by the detector. Furthermore, the high energies result in low absorption which is necessary since the beam has to travel through the entire sample in this configuration. Using this novel approach, we investigated samples consisting of 30 monolayers Au(111) deposited on H-Si(111) with a thickness of 600 µm. 10 - 20 monolayers of Co were electrochemically deposited on these substrates and analyzed by surface sensitive in situ transmission X-ray scattering. With this method the Co deposition and dissolution could be monitored under reaction conditions.