Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 90: Surface Dynamics: Experiments

O 90.6: Vortrag

Donnerstag, 23. März 2017, 11:45–12:00, WIL C107

Surface explosion of tartaric acid diastereomers on a Cu(111) surface in ultrahigh vacuum — •Alexandra Rieger and Karl-Heinz Ernst — Nanoscale Materials Science, Swiss Federal Laboratories for Materials Testing and Research (EMPA), Überlandstrasse 129, CH-8600 Dübendorf, Switzerland

Tartaric acid (TA) comes as three diastereomers: the two enantiomers L-TA and D-TA as well as the achiral meso form m-TA. We have studied the adsorption of m-TA, L-TA and the racemic mixture of L- and D-TA on a Cu(111) and on a Pd(110) surface. Using thermally desorption spectroscopy (TDS), we have investigated the thermally induced auto-catalytic decomposition reaction, the so-called surface explosion, which leads to decomposition into carbon dioxide, water and hydrogen within a very narrow temperature interval. This allows identification of structural differences in the monolayer of the isomers. X-ray photoelectron spectroscopy was used in order to identify the adsorption mode as a function of coverage. Using low-energy electron diffraction (LEED), we have investigated how the molecules self-assemble on a Cu(111) and on a Pd(110) surface.