Advertisement

Composition Profiles in Nb3Sn Diffusion Layers

  • D. B. Smathers
  • D. C. Larbalestier

Abstract

The utility of Nb3Sn as a practical superconductor has been immensely increased by the solid-state bronze-niobium process [1] for the production of Nb3Sn because it has enabled the fabrication of practical multifilamentary Nb3Sn magnet conductors for large-scale devices [2]. Current multifilamentary conductors contain 1000 to 100,000 fine filaments, about 2 to 5 μm in diameter; the Nb3Sn layer is grown during a reaction heat treatment at about 700°C after the ductile niobium and bronze have been reduced to the final composite size. Various recent studies have investigated the basic superconducting properties of the composites and the dependence of transition temperature (T c ), upper critical field (H c 2), and critical current density (T c ) on the composite makeup and reaction conditions [3,4]. The superconducting properties of Nb3Sn are strongly sensitive to the precise stress state of the Nb3Sn, the degree to which the Nb3Sn is actually Nb-25 at.% Sn and not off stoichiometry, and the extent to which additional impurity elements are present in the layer. Because of the limited information available about the chemical composition of the 1- to 2-μm-thick layers in multifilamentary Nb3Sn, it is often not clear which of these factors is controlling the superconducting properties.

Keywords

Auger Electron Spectroscopy Composition Profile Auger Signal Incident Electron Beam Sensitivity Ratio 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    M. Suenaga and W. B. Sampson, Appl. Phys. Lett. 18:584 (1971).CrossRefGoogle Scholar
  2. 2.
    D. C. Larbalestier, P. E. Madsen, J. A. Lee, M. N. Wilson, and J. P. Charlesworth, IEEE Trans. Magn. MAG-11:247 (1975).CrossRefGoogle Scholar
  3. 3.
    D. C. Larbalestier, in Proceedings of 6th International Conference on Magnet Technology, Vol. 6, ALFA Publishing Co., Bratislava, Czechoslovakia (1978), p. 1080.Google Scholar
  4. 4.
    G. Rupp, E. Springer, and J. Roth, Cryogenics 17:141 (1977).CrossRefGoogle Scholar
  5. 5.
    J. M. Morabito, Thin Solid Films 19:21 (1973).CrossRefGoogle Scholar
  6. 6.
    P. W. Palmberg, J. Vac. Sci. Technol. 13:214 (1976).CrossRefGoogle Scholar
  7. 7.
    L. E. Davis, N. C. MacDonald, P. W. Palmberg, G. E. Riach, and R. E. Weber, Handbook of Auger Electron Spectroscopy, 2nd edition, Physical Electronics Industries, Eden Prairie, Minnesota (1976).Google Scholar
  8. 8.
    J. P. Charlesworth, I. MacPhail, and P. E. Madsen, J. Mater. Sci. 5:580 (1970).CrossRefGoogle Scholar
  9. 9.
    J. D. Livingston, Phys. Status Solidi A 44:295 (1977).CrossRefGoogle Scholar
  10. 10.
    P. E. Madsen and R. F. Hills, IEEE Trans. Magn. MAG-15:182 (1979).CrossRefGoogle Scholar
  11. 11.
    T. Luhman and M. Suenaga, Appl. Phys. Lett. 29:61 (1976).CrossRefGoogle Scholar
  12. 12.
    A. W. West and R. D. Rawlings, J. Mater. Sci. 12:1862 (1974).CrossRefGoogle Scholar
  13. 13.
    V. Diaduk, J. Bostock, and M. L. A. MacVicar, IEEE Trans. Magn. MAG-15(l):610 (1979).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • D. B. Smathers
    • 1
  • D. C. Larbalestier
    • 1
  1. 1.University of Wisconsin—MadisonMadisonUSA

Personalised recommendations