Coadsorption of K and O on Ni(100) by HREEL investigation

The coadsorption of oxygen on a potassium precovered Ni(100) surface was investigated by the high resolution electron energy loss technique. The interaction between the coadsorbate atoms takes place only for a K coverage of 0.38 ML corresponding to the completion of the first K layer. At this K coverage, an intense vibrational feature, at 180 meV, is a consequence of the oscillating motion of the atoms of the Ni-K-O clusters, particularly, of the component vibrating along the surface plane.