Hostname: page-component-745bb68f8f-lrblm Total loading time: 0 Render date: 2025-02-04T01:31:11.370Z Has data issue: false hasContentIssue false
  • English
  • Français

Grain Boundary Structure and Properties of High-Tc Superconductors

Published online by Cambridge University Press:  26 February 2011

K. Jagannadham  and
J. Narayan
K. Jagannadham
Affiliation:
Department of Materials Sceince and Engineering, North Carolina State University, Raliegh, North Carolina 27695–7916
J. Narayan
Affiliation:
Department of Materials Sceince and Engineering, North Carolina State University, Raliegh, North Carolina 27695–7916
Get access

Abstract

We have modelled the grain boundaries in high-Tc superconducting oxides and determined the critical current density. The tunneling of superconducting pairs across the coalesced regions is used to determine the boundary effects. The length of the coalesced regions, with continuity of the Cu-O planes maintained by relaxation of the atom positions, is determined by minimization of the energy of the configuration. The depression of the order parameter is evaluated using the continuity conditions at the boundary in the proximity effect formulation. The excess charge distribution at the core of the boundary, determined from the solution to the Poisson's equation, is used to determine the scattering of the superconducting pairs. The width of the boundary, evaluated from modelling, determines the transmission coefficient for tunnelingof superconducting pairs. The critical current density is expressed in terms of these four important factors associated with the grain boundary. All the experimental results are explained by the present modelling of the grain boundary effects.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 275: Symposium S – Layered Superconductors: Fabrication, Properties and Applications , 1992 , 597
Copyright
Copyright © Materials Research Society 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Jagannadham, K. and Narayan, J., Phil. Mag., 61, 129 (1990).Google Scholar
2. Jagannadham, K. and Narayan, J., Mat. Sci. Engng., B8, 5 (1991).Google Scholar
3. Jagannadham, K. and Nararayn, J., Mat. Sci. Engng., B8, 201 (1991)Google Scholar
4. Jagannadham, K. and Narayan, J., Mat. Sci. Engng., in press.Google Scholar
5. Deutscher, G. and Muller, K., Phys. Rev. Lett., 59, 1745 (1987).Google Scholar
6. Deutscher, G., Physica, 153, 15 (1988)Google Scholar
7. Deutscher, G., IBM J. Res. Develop., 33, 293 (1989).Google Scholar
8. Deutscher, G., in Physics and Materials Science of High Temperature Superconductors, Ed. Kossowsky, R. et al. 1990, p. 20.Google Scholar
9. Jagannadham, K. and Narayan, J., submitted.Google Scholar
10. Narayan, J., J. Metals, 41, 18 (1988).Google Scholar
11. Manhart, J., Chaudhari, P., Dimos, D., Tsuei, C. C., and McGuire, T. R., Phys. Rev. Lett., 61, 2476 (1988).Google Scholar
12. Dimos, D., Chaudhari, P., and Manhart, J., Phys. Rev. B41, 4038 (1990).Google Scholar
13. Chaudhari, P., Manhart, J., Dimos, D., Tsuei, C. C., Chi, J., Oprysko, M. M. and Scheuermann, M., Phys. Rev. Lett., 59, 1745 (1987); Phys. rev. Lett., 60, 1653 (1988).Google Scholar
14. Dimos, D., Chaudhari, P., Manhart, J., and Legoues, F. K., Pys. Rev. Lett., 61, 219 (1988);Google Scholar
Kaplan, S. C., Chi, C. C., Chaudhari, P., Dimos, D., Gross, R., Gupta, A., and Koren, G., Phys. Rev., 43B, 8627 (1991).Google Scholar
15. Manhart, J., Gross, R., Hipler, K., Huebner, R. P., Tsuei, C. C., Dimos, D., Chaudhari, P., Science, 245, 839,(1989).Google Scholar
16. Babcock, S. E., Cai, X. Y., Kaiser, D. L., and Larbalestier, D. C., Nature, 347, 167 (1990).Google Scholar
17. Clarke, D. R., Shaw, T. M., and Dimos, D. J., Am. Ceram. Soc, 72, 1103 (1989).Google Scholar
18. De Gennes, P. G., in Superconductivity of Metals and Alloys, Bennjamin, New York, 1966, p. 227.Google Scholar
19. Nandedkar, A. S. and Narayan, J., Phil. Mag., 56, 625 (1987).Google Scholar
20. Tinkhamm, M. and Lobb, C. J., Solid State Physics, 42, 91,(1989).Google Scholar
21. Hirth, J. P. and Lothe, J., Theory of Dislocations. Ch. 14, p. 475, McGraw Hill, 1968.Google Scholar
22. Kroeger, D. M., J. Met, 41, 14,(1989).Google Scholar
23. Samsonov, G. V., The Oxide Handbook, p. 317, IFI/Plenum Publishers, New York, 1973.Google Scholar