OXYGEN-INDUCED RESTRUCTURING OF NI(110) STUDIED BY SCANNING TUNNELING MICROSCOPY

The chemisorption of oxygen on Ni(110) has been studied by scanning tunneling microscopy at room temperature. Atomically resolved STM images of the clean and the 0-covered Ni(110) surface were achieved. The formation of three O-induced reconstructions of the Ni(110) surface was identified as (3 x 1), (2 x 1) and, (3 x 1) structures corresponding to O coverages of 1/3, 1/2 and 2/3 ML. respectively. These reconstruction phases are all stabilized by -Ni-O- rows running along the [001] direction. From the nucleation and growth of these reconstruction phases, we can conclude that they are of the added-row rather than the missing-row type. From a comparison of the present results with results for O-induced restructuring of Cu and Ag surfaces. a simple physical picture evolves for the 0-induced reconstructions of the transition metals.