AVS 52nd International Symposium
    Surface Science Wednesday Sessions
       Session SS1-WeA

Paper SS1-WeA3
Atomistic Reasons for the Oxygen Induced Step Bunching on Rh(553)

Wednesday, November 2, 2005, 2:40 pm, Room 200

Session: Surface Structure and Morphology Modification
Presenter: J.N. Andersen, Lund University, Sweden
Authors: J. Gustafson, Lund University, Sweden
A. Resta, Lund University, Sweden
A. Mikkelsen, Lund University, Sweden
R. Westerstrom, Lund University, Sweden
J.N. Andersen, Lund University, Sweden
J. Weissenrieder, Lund University, Sweden
E. Lundgren, Lund University, Sweden
F. Mittendorfer, Universität Wien, Austria
G. Kresse, Universität Wien, Austria
X. Torelles, Institut de Ciencia de Materials de Barcelona (C.S.I.C), Spain
S. Ferrer, ERSF, France
N. Kasper, Max-Planck Institut f@um u@r Metalforschung, Germany
M. Schmid, Technische Universität Wien, Austria
P. Varga, Technische Universität Wien, Austria
Correspondent: Click to Email
One of the most fundamental gas-surface interactions is that between oxygen and metal surfaces. Many studies on low index single crystal surfaces have led to an atomic scale understanding of the possible dissociation pathways for the oxygen molecule and the adsorption sites of O-atoms and molecules on such flat surfaces. Oxygen interaction with vicinal surfaces - which due to their high step density better model small metal particles typically used in catalysis - has received much less attention. Similarly only few studies have been performed under conditions - higher temperatures and/or higher oxygen pressures - where strong rearrangements of the substrate surface may occur. Accordingly an atomic level understanding of the oxygen-surface interaction under conditions - material, pressure, and temperature - typical for instance for catalysis is still in its infancy. Here we present an extensive study, using a multi-method approach, of the initial oxidation of Rh(553), a surface vicinal to (111) with a large density of steps. Our results show that the surface undergoes step bunching when exposed to oxygen, forming lower index facets. At a pressure of about 10-6 mbar and a temperature of 400°C this leads to (331) facets with 1D-oxide chains along the steps, co-existing with (111) facets. Increasing the pressure and temperature further results in (111) facets only, covered by a O-Rh-O surface oxide as found on Rh(111).@footnote 1@ @FootnoteText@@footnote 1@ J. Gustafson et al., Phys. Rev. Lett. 92 (2004) 126102.