The structure of segregated Au layers on the Ni(110)–0.8 at. % Au surface has been studied by scanning tunneling microscopy. The observed structures, including (7×4) with a c(2×4) subunit, are shown to be consistent with the observed low-energy electron diffraction pattern. Two different kinds of Au structures, commensurate atomic chains and incommensurate closed-packed atomic rows, were observed. A model for the nucleation and growth of the segregated layer is proposed.

• Received 1 April 1987

DOI:https://doi.org/10.1103/PhysRevB.36.3104