Advertisement

Growth and Microstructure of YBa2Cu3O7−x Thin Films for Superconductor Devices

  • N. Savvides
  • A. Katsaros
  • C. P. Foley
  • G. J. Sloggett
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

Progress in high-T c thin film device technology is critically dependent on the quality and reproducibility of the superconducting thin films. Epitaxial c-axis YBa2Cu3O7−x thin films with smooth surfaces, controlled microstructure and crystalline orientation, and high critical current density are deposited in situ on MgO (100) substrates by on-axis dc magnetron sputtering from a stoichiometric 1–2–3 target. We use high resolution scanning electron microscopy (SEM), scanning tunneling microscopy (STM), x-ray diffraction and measurement of transport properties to study the nucleation and growth of c-axis ultrathin and thick films on plain substrates and step-edges. The films grow by the screw dislocation mediated three dimensional island growth mechanism which leads to a high density of screw dislocations, ~109 − 1011 cm−2. Typical step-edge Josephson junctions show resistively-shunted junction (RSJ) behaviour, and washer-type rf SQUIDs using these junctions have low flux noise, below 10−4Ø0/Hz1/2, and field sensitivity of 1–2 pT/Hz1/2.

Keywords

Scanning Tunneling Microscopy Screw Dislocation Epitaxial Film Ultrathin Film High Critical Current Density 
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. Hawley, I. D. Raistrick, J.C. Beery, and R. Houlton, Nature 251:1587 (1991).Google Scholar
  2. 2.
    C. Gerber, D. Anselmetti, J.G. Bednorz, J. Mannhart, and D.G. Schlom, Nature 350: 279 (1991).CrossRefGoogle Scholar
  3. 3.
    X.-Y. Zheng, D.H. Lowndes, Z. Zhu, J.D. Budai, and R.J. Warmack, Phys. Rev. 45: 7584 (1992).CrossRefGoogle Scholar
  4. 4.
    H.P. Lang, H. Hefke, G. Leeman, and H.-J. Güntherodt, Phys. C 194:81 (1992); 202: 289 (1992).Google Scholar
  5. D.G. Schlom, D. Anselmetti, J.G. Bednorz, R.F. Broom, A, Catana, T. Frey, Ch. Gerber, 11.-J. Güntherodt, H.P. Lang, and J. Mannhart, Z. Phys. B 86:163 (1992).Google Scholar
  6. 6.
    N. Savvides and A. Katsaros, Physica C (in press).Google Scholar
  7. 7.
    N. Savvides and A. Katsaros, Appl. Phys. Lett. 62: 528 (1993).Google Scholar
  8. 8.
    N. Savvides and A. Katsaros, Thin Solid Films 228: 182 (1993).CrossRefGoogle Scholar
  9. 9.
    N. Savvides, A. Katsaros, C. Andrikidis, M.P. James, C.P. Foley, D. Dart, and D.N. Matthews, in Adv. Supercon. V - 5th Int. Symp. Supercon., Nov. 16–19, Kobe, 1993.Google Scholar
  10. 10.
    E. Bauer and H. Poppa, Thin Solid Films 12:167 (1972).Google Scholar
  11. J. Mannhart, D. Anselmetti, J.G. Bednorz, A. Catana, Ch. Gerber, K.A. Müller, and D.G. Schlomm, Z. Phys. B 86:177 (1992).Google Scholar
  12. 12.
    K.P. Daly, W.D. Dozier, J.F. Burch, S.B. Coons, R. Hu, C.E. Platt, and R.W. Simon, Appl. Phys Lett. 58: 543 (1991).CrossRefGoogle Scholar
  13. 13.
    Y. Zang, H.-M. Mück„ K. Herrmann, J. Schubert, W. Zandr, A.I. Braginski, and A.I. Heiden, Appl. Phys. Lett. 60: 645 (1992).CrossRefGoogle Scholar
  14. 14.
    C.P. Foley, D.L. Dart, A. Katsaros, N. Savvides,M. James, J.C. Macfarlane, N. Scheepers, and G.J. Sloggett, IEEE Trans. Appl. Supercon. 3:2361 (1993).Google Scholar
  15. 15.
    M. Mück, IEEE Trans. Appl. Supercon. 3:2003 (1993).Google Scholar
  16. 16.
    G.J. Sloggett, D.L. Dart, C.P. Foley, R.A. Binks, N. Savvides, and A. Katsaros, Int. Superconductive Electronics Conf., Aug. 11–14, 1993, Boulder, USA.Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • N. Savvides
    • 1
  • A. Katsaros
    • 1
  • C. P. Foley
    • 1
  • G. J. Sloggett
    • 1
  1. 1.CSIRO Division of Applied PhysicsSydneyAustralia

Personalised recommendations