Oxygen induced step-bunching and faceting of Rh(553): Experiment and ab initio calculations

J. Gustafson1, A. Resta1, A. Mikkelsen1, R. Westerström1, J. N. Andersen1, E. Lundgren1, J. Weissenrieder2, M. Schmid3, P. Varga3, N. Kasper4, X. Torrelles5, S. Ferrer6, F. Mittendorfer7, G. Kresse7

1 Dept. of Synchrotron Radiation Research, Lund University, 22100 Lund, Sweden
2 MAX-Lab, Lund University, 22100 Lund, Sweden
3 Institut für Allgemeine Physik, Technische Universität Wien, 1040 Wien, Austria
4 Max-Planck Institut für Metallforschung, 70569 Stuttgart, Germany
5 Institut the Ciencia de Materials de Barcelona (C.S.I.C.), 08193, Bellaterra, Barcelona, Spain
6 European Synchrotron Radiation Facility, 28043 Grenoble Cedex, France
7 Institut für Materialphysik, Universität Wien, 1090 Wien, Austria

Phys. Rev. B 74 (2006) 035401

Using a combined experimental and theoretical approach, we show that the initial oxidation of a Rh(553) surface, a surface vicinal to (111), undergoes step bunching when exposed to oxygen, forming lower-index facets. At a pressure of about 10-6 mbar and a temperature of 380 °C this leads to (331) facets with one-dimensional oxide chains along the steps, co-existing with (111) facets. Further increase of the pressure and temperature results in (111) facets only, covered by a O-Rh-O surface oxide. Our density functional theory calculations provide an atomistic understanding of the observed behavior.

Corresponding author: J. Gustafson. Reprints also available from M. Schmid (schmid< encoded email address >).

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