We investigate the temperature dependence of the optical reflectance anisotropy (RA) of the Au( 110)-(1 × 2) surface and find that transitions involving surfacemodified bulk bands contribute to the RA spectrum. The RA peaks observed at room temperature at photon energies of 3.52 and 4.50 eV are assigned to the transitions E F → L u 1 and L 2 → L u 1 , respectively. The assignments are based upon a comparison between temperature-induced shifts in the energy of these RAS peaks and thermovariation optical spectroscopy results of the temperature dependence of transition energies between bands at the L symmetry point. The application of RAS to Au(110) can be seen as a model system for exploring surfaces in a range of environments including ultra-high vacuum,high pressures and at the solid/liquid interface. The results reported here further the understanding of the RA spectrum of the clean Au(110) surface.

We have investigated the adsorption of L-cysteine (L-Cys) onto Au(110) in an electrochemical cell and under ultra-high vacuum (UHV) conditions using reflection anisotropy spectroscopy (RAS). The L-Cys saturated surfaces created by both deposition methods exhibit similar RA profiles which indicates a similar adsorption process. Our results are consistent with L-Cys binding to the Au(110) surface through a goldthiolate (Au-S) linkage. Heating the L-Cys saturated surface in UHV to 580 K results in the decomposition of the adsorbate and leaves behind a sulphur/Au surface composed of different structural domains.

No abstract

No abstract

By utilizing reflection anisotropy spectroscopy (RAS) and scanning tunneling microscopy (STM) measurements of the ion-bombarded Cu (110) surface at low temperatures, we have developed a simple methodology for estimating the effective surface area over which irradiation-induced defects perturb surface states, leading to a reduction in the intensity of the 2.1 eV RAS peak of this surface. Each composite defect decorating an ion-impact site quenches the RAS signal in proportion to an area equivalent to approximately 170 unit cells. We estimate that an atomic defect has an effective RAS cross section with area approximately equal to that of a circle with a radius of 0.75 nm, an area equivalent to that of around 19 unit cells. Accurate determination of the coverage and spatial distribution of surface defects is a prerequisite for a coherent analytical approach to modeling the RAS data of this system.