Morphological transitions induced by oxygen on a stepped rhodium surface, Rh{332}, were studied using low-energy electron diffraction. The stable clean surface was made up of a series of six-atom-wide terraces separated by monatomic steps. At low coverages (≈0.1ML) oxygen induced a restructuring of the surface at 430 to 510K, with a doubling of step height and terrace width compared to the clean surface. With additional exposure to oxygen (0.6ML) the surface returns to the step structure of the clean sample. Both processes were reversible. A metastable double-step structure of the clean surface was produced by the catalytic removal of oxygen from the reconstructed surface with hydrogen at 360K. The kinetics of these phase transitions was investigated using low-energy electron diffraction. Kinetic modelling provides a determination of kinetic parameters for the escape of rhodium atoms from single and double step edges. A reconstruction mechanism was presented, and the driving forces were discussed.

Adsorbate-Induced Step-Doubling Reconstruction of a Vicinal Metal Surface - Oxygen on Rh {332}. G.Hoogers, D.A.King: Surface Science, 1993, 286[3], 306-16