Dispersion and Symmetry of Oxygen-Induced Bands on Al(111)

Using polarized light and angle-resolved photoelectron spectroscopy, we have shown that oxygen is bonded in an ordered (1×1) configuration on Al(111). For this model system, we have determined the symmetry and dispersion of the threee oxygen derived bands. We find two even and one odd band with respect to the ($1\overline{1}0$) mirror plane. A disordered oxide film shows no dispersion and different oxygen binding energies.