ELECTRONIC-STRUCTURE AND ADSORPTION PROPERTIES OF THE SYSTEM CS O/W(110)/

Comparative studies are carried out of the Cs/O/W(110) and Cs/W(110) a dsorption systems. The method of threshold photoemission spectroscopy is used to study the work function and electronic structure in the ene rgy region near the Fermi level as functions of the sub-monolayer cesi um coverage, A significant increase of the saturation cesium coverage is observed on the O/W(110) surface. A new adsorption-induced surface band is observed in the electronic spectrum of the system Cs/O/W(110) with a binding energy similar to 0.7 eV. For coverages of about one mo nolayer metallization of the adsorbed layer is observed. It is shown t hat the electronic structures of the systems Cs/O/W(110) and Cs/W(110) are similar for low coverages. A difference in the adsorption propert ies for these two systems occurs for coverages close to one monolayer, which is explained by the creation of new interaction centers of the Cs adatoms on the W(110) surface in the presence of oxygen. (C) 1997 A merican Institute of Physics.