Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-29T09:15:10.997Z Has data issue: false hasContentIssue false

Enhancement of Pinning Energy and Critical Current Density in Tl2CaBa2Cu2O8 Films by Proton Irradiation

Published online by Cambridge University Press:  28 February 2011

M. E. Reeves
Affiliation:
Naval Research Laboratory, Code 6344, Washington D.C. 20375–5000
B. D. Weaver
Affiliation:
Naval Research Laboratory, Code 6344, Washington D.C. 20375–5000
G. P. Summers
Affiliation:
Naval Research Laboratory, Code 6344, Washington D.C. 20375–5000 Department of Physics, University of Maryland, Baltimore County, Baltimore, MD 21228
R. J. Soulen Jr
Affiliation:
Naval Research Laboratory, Code 6344, Washington D.C. 20375–5000
W. L. Olson
Affiliation:
Superconducting Technologies, Inc., 460 Ward Dr., Santa Barbara, CA, 93111–2310 presently at Motorola AIEG, 4000 Commercial Ave., Northbrook, II 60062
M. M. Eddy
Affiliation:
Superconducting Technologies, Inc., 460 Ward Dr., Santa Barbara, CA, 93111–2310
T. W. James
Affiliation:
Superconducting Technologies, Inc., 460 Ward Dr., Santa Barbara, CA, 93111–2310
E. J. Smith
Affiliation:
Superconducting Technologies, Inc., 460 Ward Dr., Santa Barbara, CA, 93111–2310
Get access

Abstract

Measurements are presented which show the effect of proton irradiation on the irreversibility line and critical current in Tl2 CaBa2Cu2O8 thin films. These data show that the irreversibility line is dependent on the defect structure and that the pinning energy is increased by proton irradiation. This leads to an increase in the critical current density at 60 K for the lowest radiation dose. Further irradiation reduces the critical current, even while the irreversibility line is enhanced.

Type
Research Article
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. Civale, L., Marwick, A. D., McElfresh, M. W., Worthington, T. K., Malozemov, A. P., Holtzberg, F. H., Thompson, J. R., Kirk, M. A., Phys. Rev. Lett. 65, 1164 (1990).Google Scholar
Civale, L., McElfresh, M.W., Marwick, A.D., Holtzberg, F.H., Feild, C., Thompson, J.R., and Christen, D.K., Phys. Rev. B 43, 13732 (1991).Google Scholar
2. Kiipfer, H., Keller, C., Meier-Hirmer, R., Salama, K., Selvamanickam, V., and Tartaglia, G.P., IEEE Trans, on Magnetics, 27, 1369 (1991).Google Scholar
3. Venturini, E.L., Barbour, J.C., Ginley, D.S., Baughman, R.J., and Morosin, B., Appl. Phys. Lett. 56, 2456 (1990).Google Scholar
4. Kramer, Edward J., J. Appl. Phys. 44, 1360 (1973).Google Scholar
5. Reeves, M.E., Weaver, B.D., Krieger, D.A., Chrisey, D.B., Horwitz, J.S., Wolf, S.A., and Summers, G.P., to be published in Phys. Rev. B 45 (1992).Google Scholar
6. Weaver, B. D., Reeves, M. E., Summers, G. P., Soulen, R. J., Olson, W. L., Eddy, M. M., James, T. W., and Smith, E. J., Appl. Phys. Lett. 59, 2600 (1991).Google Scholar
7. Weaver, B. D., Reeves, M. E., Chrisey, D. B., Summers, G. P., Olson, W. L., Eddy, M. M., James, T. W., and Smith, E. J., J. Appl. Phys. 69, 1119 (1991).Google Scholar
8. Claassen, J. H., Reeves, M. E., Soulen, R. J. Jr, Rev. Sci. Inst. 62, 996 (1991).Google Scholar
9. Fiory, A.T., Hebard, A.F., Mankiewich, P.M., and Howard, R.E., Appl. Phys. Lett, 52, 2165 (1988).CrossRefGoogle Scholar
10. Ekin, J.W., Appl. Phys. Lett., 55, 905 (1989).Google Scholar
11. The E-J curve is calculated from the experimentally measured third-harmonic voltage vs. coil current curve. The electric field (E) at the film is calculated as (l/2πrc) (dφc /dt) where φc is the flux contain within a radius rc, the mean radius of the coil. At low distortion levels, the third harmonic voltage is proportional to φ;c. To plot E vs. J, the critical current density is estimated to be the sheet-current induced in a perfectly conducting film divided by the film thickness. The estimates for E and J are accurate in the limit where the ac field is effectively screened by currents induced in the film. In this experiment, the ac currents are low enough that this condition is satisfied.Google Scholar
12. Tinkham, M, Introduction to Superconductivity, (Krieger, Robert E., Malabar, Florida 1980).Google Scholar