Skip to main content
Bulk and Surface Singularity Indices in the Alkali Metals
Physical Review B
  • G. K. Wertheim
  • D. Mark Riffe, Utah State University
  • P. H. Citrin
Document Type
Publication Date
Photoemission data from (110) films of Li, Na, and Rb, in which the signal from the first atomic layer is well resolved, show that the core-hole-screening singularity index is ∼40% larger at the surface than in the bulk for all three metals. This result, which is indicative of the more atomiclike character of metal surface atoms, in general, is particularly large for the alkali metals because their conduction-electron screening is mainly s-like. In addition to quantifying the difference in screening at the surface, the data provide bulk singularity indices of 0.22, 0.16, and 0.14 for Li, Na, and Rb, respectively. These new values are in better agreement with theory and with the threshold exponents than earlier values derived from incompletely bulklike x-ray photoemission data.

Published by American Physical Society in Physical Review B. Publisher PDF is available for download through link above.

Citation Information
"Electron Mean-Free Paths in the Alkali Metals," G. K. Wertheim, D. M. Riffe, N. V. Smith, and P. H. Citrin, Phys. Rev. B 46, 1955 (1992).