Local-field effects and electronic anisotropy of the (1×2) reconstructed Au(1 1 0) surface

• Published in: Physica A 2001-09, Vol.298 (1), p.46-55
• Main Authors: Hansen, J.-K., Bremer, J., Seime, L., Hunderi, O.
• Format: Article
• Language: English
• Subjects: Electronic structure; Gold; Reflection spectroscopy; Surface; Surface reconstruction
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/S0378-4371(01)00210-2

The local-field theory is applied to the (1×1) and the (1×2) reconstructed (1 1 0) surfaces of noble metals. Calculated curves for the unreconstructed and reconstructed Au(1 1 0) surfaces are compared. In both cases, a dispersion-shaped profile is present at 2.55 eV . The spectrum for the (1×2) case shows a significantly stronger anisotropy than in the unreconstructed case. An experimental study has been made of the reflection anisotropy for the clean Au(1 1 0) surface at room temperature, where a (1×2) reconstruction is present, in order to test the validity of the calculations. The measured spectrum has a broad minimum in the range 2– 4 eV with two sharp structures at 2.4 and 3.4 eV , respectively. The feature at 2.4 eV and the broad minimum is attributed to the effect of the screened local-field on d-band transitions at the surface. The influence of broadening and shifts in critical-point energies for the surface principal directions is discussed.