Sun L D, Hohage M, Zeppenfeld P, Balderas-Navarro R E, Hingerl K
Institut für Experimentalphysik, Johannes Kepler Universität Linz, A-4040 Linz, Austria.
Phys Rev Lett. 2003 Mar 14;90(10):106104. doi: 10.1103/PhysRevLett.90.106104. Epub 2003 Mar 13.
Reflectance difference spectroscopy is used to probe the optical transitions between surface states on the Cu(110) surface. Upon deposition of smallest amounts of carbon monoxide (CO) the signal is strongly quenched, which translates into a huge cross section of the order of 1000 A(2) for a single adsorbed CO molecule. This strongly enhanced surface sensitivity is interpreted as the loss in anisotropy (depolarization) of the surface states due to scattering from the adsorbed CO molecules. This feature renders RDS an extremely sensitive tool to probe the adsorption kinetics on anisotropic metal surfaces.