Superconductivity of BCC Barium under Pressure

  • J. Wittig
  • C. Probst


The bcc phase of barium is a superconductor. Tc increases steeply with pressure from 0.06 K at 37 kbar to 0.5 K at 48 kbar. A fit of McMillan’s expression for Tc suggests a Tc already in the millikelvin range at 30 kbar. Phonon softening as inferred from the decreasing melting curve is insufficient to account for the rise of Tc with pressure. A He3/He4 dilution refrigerator is described which allows high pressure experiments at temperatures down to 0.05 K.


Radiation Shield Dilution Refrigerator Disk Spring Press Body Lower Anvil 
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.
    J. Wittig and B.T. Matthias, Phy. Rev. Lett. 22, 634 (1969).CrossRefGoogle Scholar
  2. 2.
    A.R. Moodenbaugh and J. Wittig, J. Low Temp. Phys. 10, 203 (1973).CrossRefGoogle Scholar
  3. 3.
    The onset of superconducting transitions has been repeatedly observed at 1.3 K and 55 kbar (unpublished results) pointing to a Tc of approximately 1 K for Ball at this pressure.Google Scholar
  4. 4.
    A large rise of the room-temperature resistance occurs at the III-IV transformation [e.g. ref. 1]. It can however not be attributed to an increase of the electron-phonon interaction. It is caused by an anomalous increase of the residual resistivity in the phase BaIV (unpublished data).Google Scholar
  5. 5.
    A. Jayaraman, W. Kiement, Jr., and G.C. Kennedy, Phys. Rev. Lett. 10, 387 (1963).CrossRefGoogle Scholar
  6. 6.
    J.P. Bastide and C. Susse, High Temperatures-High Pressures 2, 237 (1970).Google Scholar
  7. 7.
    A. Eichler and J. Wittig, Z. Angew. Physik 25, 319 (1968).Google Scholar
  8. 8.
    A.C. Anderson, Rev. Sci. Instrum. 41, 1446 (1970).CrossRefGoogle Scholar
  9. 9.
    D.L. Decker, W.A. Bassett, L. Merrill, H.T. Hall, and J.D. Barnett, J. Phys. Chem. Ref. Data 1, 773 (1972).CrossRefGoogle Scholar
  10. 10.
    W.L. McMillan, Phys. Rev. 167, 10 (1968).CrossRefGoogle Scholar
  11. 11.
    B. Chakraborty, W.E. Pickett, and P.B. Allen, Phys. Rev. B14, 3227 (1976).Google Scholar
  12. 12.
    B.L. Gyorffy, in Superconductivity in d- and f-Band Metals, edited by D.H. Douglass, Jr. (Plenum Press, N.Y., 1976), p. 29.CrossRefGoogle Scholar
  13. 13.
    B. Vasvari, A.O.E. Animalu, and V. Heine, Phys. Rev. 154, 535 (1967).CrossRefGoogle Scholar
  14. 14.
    D.C. Hamilton, Amer. J. Phys. 33, 637 (1965).CrossRefGoogle Scholar
  15. 15.
    B.T. Matthias, W.H. Zachariasen, G.W. Webb, and J.J. Engelhardt, Phys. Rev. Rev. Lett. 18, 781 (1967).CrossRefGoogle Scholar
  16. 16.
    K.A. Gschneidner, Jr., J. Less-Common Metals 25, 405 (1971).CrossRefGoogle Scholar
  17. 17.
    J. Wittig, Comments Solid State Physics VI, 13 (1974).Google Scholar
  18. 18.
    C. Probst and J. Wittig, in Handbook of the Physics and Chemistry of Rare Earths, edited by K.A. Gschneidner, Jr., and LeRoy Eyring (North Holland Publishing Co., Amsterdam) Chapter 10, in print.Google Scholar
  19. 19.
    C.E. Moore, Atomic Energy Levels (National Bureau of Standards, Circular No. 499, U.S. Government Printing Office, Washington, D.C., 1950), Vols. 2 and 3.Google Scholar
  20. 20.
    J.P. Connerade and M.W.D. Mansfield, Proc. R. Soc. Lond. A 346, 465 (1975) and references therein.Google Scholar

Copyright information

© Plenum Press, New York 1978

Authors and Affiliations

  • J. Wittig
    • 1
  • C. Probst
    • 1
  1. 1.Institut für FestkörperforschungKernforschungsanlage JülichWest-Germany

Personalised recommendations