AN ELECTRON DIFFRACTION STUDY OF CESIUM ADSORPTION ON TUNGSTEN

Surface structures, work function changes, Auger electron losses and surface plasma losses have been studied for the adsorption of cesium on clean surfaces of tungsten. The first structures observed to form on both the (100) and (110) surfaces are due to the adsorption of cesium in an ionic form, while the last structures are due to a second layer of metallic cesium. This last structurre is the same for both surfaces, being a hexagonal close-packed arrangement of cesium atoms. That this structure on the (100) surface is metallic is evidenced by the observation of a cesium surface plasmon peak that increases in intensity as the hexagonal array is formed. The work function minimum is characterized by a definite two-dimensional structure. © 1969.