Angle-resolved photoemission study of the interaction of oxygen with a Ni(110) surface

The electronic state of oxygen adsorbed on a Ni(110) surface at 300 K has been studied by angle-resolved photoemission spectroscopy using polarized synchrotron radiation. For the low-coverage (3×1)-O and subsequent (2×1)-O adsorbed structures, a dispersion of the O 2p-derived levels is observed, indicative of adsorbate band formation with a two-dimensional Bloch character. The energy bands of the O 2p and Ni 3d valence levels for NiO(100) formed on Ni(110) are also mapped out. The experimental results for the (3×1)-O and (2×1)-O are compared with the dispersion predicted for isolated oxygen monolayers in the respective configurations from a tight-binding model.