Surface diffusion of oxygen atoms individually observed by STM

We report on the first dynamical studies with scanning tunneling microscopy (STM). Single excess oxygen atoms migrating on the oxygen-induced (2 × 1) and c(2 × 2) reconstructions on Ni(110) and Ni(100), respectively, are detected space and time resolved. In principle, for varying temperature, the data reveal the local diffusion coefficient, the activation energy and the density of adatoms on terraces and at steps. For the Ni(110) (2 × 1), even the adsorption sites are identified. © 1986.