INVESTIGATION OF ALKALI-METALS AND NOBLE-GASES ADSORBED ON TRANSITION-METALS USING CIRCULAR-DICHROISM IN ANGULAR RESOLVED PHOTOEMISSION

We investigated the adsorption of alkali metals an noble gases on tran sition metal surfaces. These serve as atom-like adsorbates to be compa rable to calculations of the Circular Dichroism in the Angular Distrib ution of photoelectrons (CDAD) including backscattering at the substra te surface and photoelectron diffraction within the adsorbate layer. O ur calculations show the influence of scattering and diffraction, that even can generate a dichroism where none should be. For the case of t he 4p(1,2)-subshell of Rb our calculations agree well with our measure ments. For the 4p(3/2)-subshell we found a different behaviour due to a polarisation of the state in the adsorbed layer. We also present fir st results for CDAD from noble gases. The 5p - states from Xe show les s atomic-like behaviour, because they are much more weakly bound and f orm bands.