Nature of the ns-derived states for an isolated alkali atom on a surface

• Published in: Surface science 1999, Vol.429 (1), p.309-319
• Main Authors: Sandell, A., Brühwiler, P.A., Nilsson, A., Bennich, P., Rudolf, P., Mårtensson, N.
• Format: Article
• Language: English
• Subjects: Adsorbed layers and thin films; Alkali metals; Chemisorption; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Impurity and defect levels; energy states of adsorbed species; Photoemission and photoelectron spectra; Physics; Single crystal surfaces; Soft X-ray photoelectron spectroscopy; Surface and interface electron states; Surface electronic phenomena
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(99)00393-3

It has recently been shown (for K/graphite) that experimental core level spectroscopy data for adsorbed Ar combined with calculations is a most valuable tool in order to obtain information about the alkali-derived unoccupied density-of-states [A. Sandell et al., Phys. Rev. Lett. 78 (1997) 4994]. We present experimental results for Ar on various metallic substrates and discuss them in terms of adsorption properties of an isolated K adatom. We find a clear tendency for increased 4s–substrate mixing as the substrate work function decreases, in accordance with a simple extension of the Gurney model. It is also shown that core level spectroscopy data for Ar coadsorbed with K can be used to investigate the effects on the 4s resonance of increasing K coverage.