Optical anisotropy of nanostructured noble metal surfaces

Abstract

The reflection anisotropy spectra of the noble metal (110) surfaces are discussed in terms of surface modified bulk transitions within the derivative model and derivative model parameters for a range of variously structured surfaces are presented. The utility and consistency of the derivative model in explaining noble metal spectra is demonstarted. RAS spectra of ion bombarded noble metal surfaces are explained in terms of roughness induced uncertainty in the electronic wavevectors in the surface region. Spectra of nanostructured Cu(110) surfaces are presented and discussed. Contrasting spectral evolution during annealing for the (110) and (771) surfaces is attributed to differing step densities © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 Introduction As it is increasingly understood that an overwhelming range of physical phenomena derive from the microscopic properties of materials, it becomes ever more important to understand and control the properties of surfaces at the nanoscale. As such reflection anisotropy spectroscopy (RAS) [1], an epioptic technique with sub-monolayer sensitivity, is being applied to an ever broader range of systems [2]. RAS measures the quantity ∆r/r, the normalised difference in complex reflectance for light polarised in two orthogonal directions at normal incidence,