STUDY OF CLEAN AND OXYGEN-COVERED AG SURFACES USING OPTICAL REFLECTANCE ANISOTROPY

We report measurements of the azimuthal anisotropy in the normal incid ence reflectance of clean and adsorbate-covered single crystal Ag(110) surfaces. Reflectance anisotropy spectra were taken between 1.5 and 5 .5 eV photon energy. Previous studies in air had indicated a very larg e anisotropy in the region around the surface plasmon energy. On the c lean surface this feature is strongly reduced compared to that observe d on a contaminated surface. By oxygen dosage the (1 x 1) surface stru cture is modified to (4 x 1) and (2 x 1) as displayed by LEED. The sim ultaneously observed optical anisotropy shows a correlation with oxyge n coverage and restores to a large extent the anisotropy observed in a ir.