Local-Field Effects at the Ag(110) and Cu(110) Surfaces Studied by Reflection Anisotropy Spectroscopy

We have calculated the screened surface local-field effect for the f.c.c. (110) case, and applied the results to Cu and Ag. Theoretical reflection anisotropy spectra are compared with experimental ones for both clean and oxygen covered surfaces between 1.8 and 5.5 eV. In the Cu(110) case, there is a satisfactory agreement. For the clean Ag(110) surface, the surface seems to exist in two different states resulting in two qualitatively different RAS spectra. Only one of them can be modelled reasonably well by surface local-field effect theory. In addition, we investigate how the variation in model parameters change the form of the spectra of Ag(110).