The reflectance anisotropy of a clean Al(110)-vacuum interface has been measured experimentally, and compared with the results of an ab-initio self-consistent full-potential linear augmented plane-wave calculation. Good agreement is found in the interband regime, while a discrepancy in the Drude regime is consistent with anisotropy in the intraband contribution. The calculated surface dielectric anisotropy and reflectance anisotropy of Al(110) are not significantly affected by surface relaxation, suggesting that optical transitions between surface states and surface resonances make only a minor contribution to the surface dielectric response. The measured reflectance anisotropy of Al(110) is found to be only weakly affected by oxidation and by the deposition of Ni overlayers, providing further evidence in support of this conclusion.

• Received 16 October 2003

DOI:https://doi.org/10.1103/PhysRevB.69.165406