Journal of Low Temperature Physics

, Volume 47, Issue 1–2, pp 27–37 | Cite as

Effect of mixed valence impurities on superconductivity

  • P. Schlottmann


The phase transition temperatureT c , the specific heat discontinuity ΔC, and the critical magnetic field of a superconductor containing intermediate valence impurities are calculated. The impurities are described by the Anderson model with orbital degeneracy in theU → ∞ limit when two active ionic configurations, corresponding to4f0 and4f1 (Ce impurities), are present. The properties of the superconducting alloy are expressed in terms of thet-matrix for the scattering off the impurities. It is assumed that no correlation between the impurities exists. The transition temperature decreases approximately exponentially with the impurity concentration as for the spin-fluctuation limit and the strong coupling Kondo limit. The critical field deviation functionD(T/T c ) is the same as for the BCS theory. This indicates pair weakening rather than pair breaking, which is consistent with the picture that the mixed valence problem is driven by charge fluctuations, while spin fluctuations play only a secondary role.


Critical Field Anderson Model Mixed Valence Spin Fluctuation Field Deviation 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M. B. Maple, inMagnetism, Vol. V, H. Suhl, ed. (Academic Press, New York, 1973), p. 289.Google Scholar
  2. 2.
    P. W. Anderson,Phys. Rev. 124, 41 (1961).Google Scholar
  3. 3.
    A. A. Abrikosov and L. P. Gorkov,Zh. Eksp. Teor. Fiz. 39, 1781 (1960) [Sov. Phys.—JETP 12, 1243 (1961)].Google Scholar
  4. 4.
    E. Müller-Hartmann and J. Zittartz,Phys. Rev. Lett. 26, 482 (1971).Google Scholar
  5. 5.
    A. Ludwig and M. J. Zuckermann,J. Phys. F 1, 516 (1971).Google Scholar
  6. 6.
    P. Schlottmann,Solid State Commun. 16, 1297 (1975);J. Low Temp. Phys. 20, 123 (1975).Google Scholar
  7. 7.
    T. Matsuura and Y. Nagaoka,Solid State Commun. 18, 1583 (1976).Google Scholar
  8. 8.
    A. Sakurai,Phys. Rev. B 17, 1195 (1978).Google Scholar
  9. 9.
    A. B. Kaiser,J. Phys. C 3, 410 (1970).Google Scholar
  10. 10.
    P. Schlottmann,Solid State Commun. 21, 663 (1977).Google Scholar
  11. 11.
    C. Wiecko and A. López,J. Low Temp. Phys. 24, 117 (1976).Google Scholar
  12. 12.
    C. Wiecko and A. López,Solid State Commun. 23, 131 (1977).Google Scholar
  13. 13.
    R. Allub, C. Wiecko, and B. Alascio,Phys. Rev. B 23, 1122 (1981).Google Scholar
  14. 14.
    C. M. Varma,Rev. Mod. Phys. 48, 219 (1976).Google Scholar
  15. 15.
    T. V. Ramakrishnan, inProceedings of the International Conference on Valence Fluctuations in Solids (Santa Barbara, 1981), L. M. Falicov, W. Hanke, and M. B. Maple, eds. (North-Holland, 1981), p. 13.Google Scholar
  16. 16.
    J. H. Jefferson,J. Phys. C 10, 3589 (1977); F. D. M. Haldane,Phys. Rev. Lett. 40, 416 (1978).Google Scholar
  17. 17.
    M. Kiwi and M. J. Zuckermann,Phys. Rev. 164, 548 (1967).Google Scholar
  18. 18.
    H. Shiba,Progr. Theor. Phys. (Kyoto)50, 50 (1873).Google Scholar
  19. 19.
    F. Steglich, J. Aarts, C. D. Bredl, W. Lieke, D. Meschede, W. Franz, and H. Schäfer,Phys. Rev. Lett. 43, 1892 (1979).Google Scholar
  20. 20.
    J. G. Huber and M. B. Maple,J. Low Temp. Phys. 3, 537 (1970).Google Scholar
  21. 21.
    C. A. Luengo, J. M. Cotignola, J. Sereni, A. R. Sweedler, M. B. Maple, and J. G. Huber,Solid State Commun. 10, 459 (1972).Google Scholar

Copyright information

© Plenum Publishing Corporation 1982

Authors and Affiliations

  • P. Schlottmann
    • 1
  1. 1.Institut für Theoretische PhysikFreie Universität BerlinBerlinGermany

Personalised recommendations