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Temperature Effect in Surface Reconstruction of Clean and Hydrogen-Adsorbed W(001) Surface

  • T. Matsubara
Part of the Springer Series in Solid-State Sciences book series (SSSOL, volume 59)

Abstract

It is now well-known that the clean W(001) surface undergoes a reconstructive phase-transition at certain temperature Tc and exhibits a c(2×2) structure at low temperatures. From various experimental and theoretical sources, it is concluded that this surface reconstruction is a second order transition caused by spontaneous displacements of surface atoms along a direction parallel to the surface as depicted in Fig.1 [1]. The reconstructed structure of W(001)is somehow stabilized when hydrogen atoms are adsorbed, so long as the coverage of hydrogen is small [2], As to the mechanism of the phase-transition, several models have been proposed [3], but at present it seems that an accepted view point is to attribute the origin of driving transition to the competition between stabilizing band electronic force and opposing ion-core repulsive force. Among others, TERAKURA et al. gave an electronic theory of the surface reconstruction on W(001) [4] which could explain even quantitatively the relevant experimental facts for absolute zero T=0. As to temperature-variation of this transition, however, there are a few theories in which the temperature-effect is seriously considered. Probably this is due to the fact that the main source of information on the temperature-dependence of the “order parameter” is LEED experiments, which are much influenced by large surface vibration as far as the temperature-effect is concerned. Indeed, for instance, we can observe in Fig.2, with increasing temperature, strong exponential decay of the scattering intensity of the LEED patterns characteristic to the low-temperature phase [5]. If we look at Fig.2 as a temperature-dependence curve for the “order parameter” of the phase-transition, it would be quite unusual in contrast to the standard behaviour of the order parameter in the second order phase-transition: The transition-temperature is obscured by the exponential tail.

Keywords

Surface Reconstruction Atomic Displacement Integral Order Exponential Tail LEED Pattern 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    D. A. King : Physica Scripta T4, 34(1983).CrossRefGoogle Scholar
  2. 2.
    M. K. Debe and D. A. King : J. Phys. C10, L1303 (1977).Google Scholar
  3. T. E. Felter, R. A. Barker and P. J. Estrup : Phys. Rev. Lett. 38, 1138 (1977).CrossRefGoogle Scholar
  4. 3.
    J. E. Inglesfields : Vacuum 31, 663 (1981).CrossRefGoogle Scholar
  5. 4.
    K. Terakura, I. Terakura and Y. Teraoka : Surface Sci. 80, 535 (1979).CrossRefGoogle Scholar
  6. I. Terakura, K. Terakura and N. Hamada : Surface Sci. 103, 103 (1981)CrossRefGoogle Scholar
  7. K. Masuda-Jindo, N. Hamada and K. Terakuka : J. Phys. C17, L271 (1984)Google Scholar
  8. 5.
    D. A. King and G. Thomas : Surface Sci. 72, 201 (1980)CrossRefGoogle Scholar
  9. 6.
    R. A. Barker and P. J. Estrup : J. Chem. Phys. 74, 1442 (1981)CrossRefGoogle Scholar
  10. 7.
    M. K. Debe and D. A. King : Surface Sci. 81, 193 (1979)CrossRefGoogle Scholar
  11. 8.
    T. Matsubara and K. Kamiya : Prog. Theor. Phys. 58, 767 (1977).CrossRefGoogle Scholar
  12. T. Matsubara, Y. Iwase and A. Momokita : Prog. Theor. Phys. 59, 1102 (1978).Google Scholar
  13. T. Hama and T. Matsubara : Prog. Theor. Phys. 59, 1407 (1978).CrossRefGoogle Scholar
  14. 9.
    K. H. Lau and S-C. Ying : Phys. Rev. Lett. 44, 222 (1980)CrossRefGoogle Scholar
  15. 10.
    T. Inaoka and A. Yoshimori : Surface Sci. 115, 301 (1982).CrossRefGoogle Scholar
  16. 11.
    T. Matsubara and T. Odagaki : in preparation.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1985

Authors and Affiliations

  • T. Matsubara
    • 1
  1. 1.Department of PhysicsKyoto UniversityKyoto 606Japan

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