The oxygen adsorption on the unreconstructed Rh(110) surface was studied by scanning tunnelling microscopy, by imaging the evolution of the surface reconstruction in situ during oxygen uptake at 390K. The dynamics terminate with the formation of a strained (10 x 2)–O structure with high local oxygen coverage. Initially, kink atoms were detached from the steps and diffuse over the surface, most probably as Rh–O units, as inferred by comparison to X-ray photo-electron spectroscopy data, until they condense in zig-zag structures characteristic for the (2 x 2)p2mg–O structure (0.5ML). At oxygen doses above 0.12L, missing rows began to be dug along the [1¯10] direction into the steps, detaching further Rh atoms. The reconstruction proceeded as a missing/added row reconstruction. With ongoing surface reconstruction, a second reconstruction mechanism of local nature sets in: Rh atoms start to be ejected out of the terraces and condense at the ends of the so formed troughs. Dosing further oxygen on the (2 x 2)p2mg–O structure led to the formation of the strained (10 x 2)–O structure. The ejection of two of every 10 Rh atoms proceeded only if the Rh rows were not neighboured by troughs.

Dynamics of the O Induced Reconstruction of the Rh(110) Surface - a Scanning Tunnelling Microscopy Study. C.Africh, F.Esch, G.Comelli, R.Rosei: Journal of Chemical Physics, 2001, 115[1], 477