Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 23: Oberfl
ächenreaktionen II
O 23.4: Vortrag
Dienstag, 25. März 2003, 15:45–16:00, M\"UL/ELCH
Oxygen dissolution versus surface defects at Ru(0001) — •Raoul Blume1, Artur Böttcher2, and Horst Niehus1 — 1Humboldt Universität zu Berlin, Institut für Physik, ASP, Invalidenstr. 110, 10115 Berlin — 2Universität Karlsruhe (TH), Institut für Physikalische Chemie, Fritz-Haber-Weg 4, 76131 Karlsruhe
The role of surface defects on the low-temperature and high pressure oxygen dissolution in Ru(0001) (T < 600K, p ≤ 1bar) has been studied by the means of TDS, LEED, elastic He-scattering and the reactive CO-scattering. Surface defects have been generated by applying different Ar+ -sputtering conditions. The resulting integral surface roughness has been determined by He-scattering. The formation, thermal removal and the reactivity of the low-temperature oxygen phases created depend strongly on the defect density. Defects raise the surface capability for oxygen dissolution in the subsurface region. In comparison to a smooth surface the defect-rich surface exhibits a higher reactivity to the CO-oxidation reaction. The low-temperature oxidation procedures applied to a defected surface do not result in oxide growth even for oxygen exposures higher than 1014 L where a smooth surface already starts to oxidize.