Regensburg 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 44: Poster Session II (Semiconductors; Oxides and Insulators: Adsorption, Clean Surfaces, Epitaxy and Growth; Surface Chemical Reactions and Heterogeneous Catalysis; Surface or Interface Magnetism; Solid-Liquid Interfaces; Organic, Polymeric, Biomolecular Films; Particles and Clusters; Methods: Atomic and Electronic Structure; Time-resolved Spectroscopies)

O 44.66: Poster

Mittwoch, 28. März 2007, 17:00–19:30, Poster C

In situ STM study of the adsorption and oxidation of sulfide on the Au(1 0 0) surface — •Christian Schlaup, Daniel Friebel, Peter Broekmann, and Klaus Wandelt — Institut für Physikalische und Theoretische Chemie, Wegelerstr. 12, D-53115 Bonn

In contrast to the well described adsorption behavior of sulfide on the Au(1 1 1) surface, the adsorption of sulfide on the Au(1 0 0) surface has not yet been part of extensive investigation. In 0.01 M NaOH / 0.5 mM Na₂S electrolyte, the formation of different ordered sulfide adsorbate layers could be detected. Depending on the applied electrochemical potential a simple p(2 × 2) (Θ_S = 0.25 ML), a more complex c(2 × 6) (Θ_S = 0.33 ML) or a c(2 × 2) (Θ_S = 0.5 ML) overlayer is formed. The well-known Au(1 0 0)-(hex) reconstruction, which could be observed at cathodic potentials, is lifted during the initial stages of sulfide adsorption leading to the formation of small, well oriented gold islands. By increasing the S coverage from initially Θ_S = 0.25 ML, the shape of these islands changes significantly to a serrated form. Thereby a complex bi-layer phase, coexisting with the c(2 × 6) S adlayer, is formed. Upon further oxidation, the characteristic ring-like structure appears, which has already been observed on the S-covered Au(1 1 1) surface at high potentials (EC) and high S coverage (UHV), respectively.