Surface morphology of Au(111) after exposure to oxygen at high temperature and pressure

• Published in: Surface science 1996-05, Vol.352, p.285-289
• Main Authors: Huang, L., Zeppenfeld, P., Chevrier, J., Comsa, G.
• Format: Article
• Language: English
• Subjects: Chemisorption; Gold; Low index single crystal surfaces; Oxygen; Scanning tunnelling microscopy; Surface structure, morphology, roughness, and topography
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(95)01148-X

We report a scanning tunnelling microscopy (STM) study of the surface morphology of Au(111) exposed to oxygen at high temperature (700–800°C) and high pressure (1 bar). Two types of oxygen induced surface structures were observed: (i) a hexagonal long-range reconstruction [L. Huang et al., Appl. Phys. Lett. 66 (1995) 211] with a periodicity of ∼ 65 A ̊ and a corrugation of about 0.5 Å. At the atomic scale this surface exhibits a (√3 × √3)R30° structure, which we attribute to atomic oxygen strongly chemisorbed at the Au(111) surface. (ii) a “modified” herringbone pattern related to the original herringbone reconstruction of the clean Au(111) surface, but with additional depressions in some of the fcc-regions between the reconstruction lines. At the atomic scale this surface exhibits a characteristic “row structure” with √3 periodicity. For both structures the dependence of the STM image contrast on the tunnelling parameters was investigated.