Elsevier

Surface Science

Volume 126, Issues 1–3, 2 March 1983, Pages 618-623
Surface Science

Effect of parallel velocity on charge fraction in ion-surface scattering

https://doi.org/10.1016/0039-6028(83)90766-5Get rights and content

Abstract

The negative charge fraction in proton scattering from Cs-covered W(110) is found experimentally to be a strong function of parallel velocity V as well as perpendicular velocity v⊥ entering in previous theoretical treatments. Theory shows that V may be taken into account by displacing the Fermi sphere in existing theory by Q=mV. A simple model and a more complete calculation explain the H+ data. Extension to the case of Na atomic beams on clean W(110) shows that the V-effect is too small to explain discrepancies between theory and experiment at low T.

References (11)

  • R. Brako et al.

    Surface Sci

    (1981)
  • R. Brako et al.

    Vacuum

    (1982)
    J.K. Nørskov et al.

    Phys. Rev.

    (1979)
  • K.L. Sebastian et al.

    Surface Sci.

    (1981)
  • J.N.M. van Wunnik, J.J.C. Geerlings and J. Los, Surface Sci,...F. Guinea-Lopez et al.

    Phys. Rev. Letters

    (1981)
  • M.L. Yu

    Phys. Rev. Letters

    (1981)
There are more references available in the full text version of this article.

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On leave of absence from Faculty of Engineering Science, Osaka University, Toyonaka, Osaka, Japan.

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