ALKALI-METAL AND TRANSITION-METAL ADSORPTION ON METAL-SURFACES STUDIED BY WORK FUNCTION MEASUREMENTS

Elementary aspects of adsorption phenomena which are intimately connected to dipole layers of both homo- and heterogeneous adsystems are outlined. The Newns-Anderson model of chemisorption has been consistently reformulated within the density functional theory and thus related to first principles. Work function measurements and supplementary methods (e.g. LEED, UPS, EELS, and MDS etc.) on K/Ni(100) at 40 K show unexpected deviation from the Langmuir behaviour in the low coverage region (beyond 1 ML). Experimental results for the initial dipole moment are obtained and discussed within the framework of the Topping-model.