Observation of a missing-row structure on an fcc (111) surface: The (5 √3 ×2)S phase on Ni(111) studied by scanning tunneling microscopy

A missing-row reconstruction of an fcc (111) metal surface has been observed for the first time. Direct observation of many small islands formed at the surface during S adsorption on Ni(111) indicates that a long-range mass transport takes place and that the surface undergoes a reconstruction. We present evidence that this reconstruction corresponds to a model in which every fifth Ni 〈110〉 surface row is missing, with a total of 0.4 monolayer of S atoms adsorbed in threefold hollow positions on the surface and in the created troughs. The driving force for this novel missing-row reconstruction is proposed to be adsorption-induced surface stress.