Electromagnetic properties and He+ irradiation effects on YBa2Cu3O7-x grain-boundary Josephson junctions

Thumbnail Image
Full text at PDC
Publication Date
Advisors (or tutors)
Journal Title
Journal ISSN
Volume Title
American Physical Society
Google Scholar
Research Projects
Organizational Units
Journal Issue
We have analyzed the electromagnetic properties of small and long YBa2Cu3O7-x grain-boundary Josephson junctions. The Swihart velocity increases with junction width (rv) while the ratio of the relative dielectric constant to the barrier thickness (epsilon/t) decreases. We found that the product wX epsilon/t is approximately constant. These results have been explained in the framework of the filamentary model, where the barrier can be regarded as a disordered dielectric medium with a high density of superconducting filaments. Experiments demonstrate that a controllable variation of these parameters can be achieved by helium irradiation at 80 keV. We give examples of an enhancement of weak-link properties of junctions for doses in the range of 10(13) cm(-2) Raising the dose we can sweep the modification of the weak-link properties from an increase of the junction critical current of about 10% to a severe degradation of the coupling energy of the barrier, although the superconducting properties of the electrodes always worsen gradually.
© The American Physical Society. The authors would like to thank C. A. I. de Implantación Iónica from the Universidad Complutense in Madrid for assistance with ion implantation and lithography facilities. Financial support from CICYT Grant No. MAT97-0675 is acknowledged.
Unesco subjects
1) S. Pagano and A. Barone, Supercond. Sci. Technol., 10, 904 (1997). 2) N. F. Heinig, R. D. Redwing, I. Fei Tsu, A. Gurevich, J. E. Nordman, S. E. Babcock, and D. C. Larbalestier, Appl. Phys. Lett., 69, 577 (1996). 3) D. Dimos, P. Chaudhari, J. Mannhart, and F. K. LeGoues, Phys. Rev. Lett., 61, 219 (1988). 4) T. Ogawa and M. Koyanagi, Appl. Phys. Lett., 70, 2183 (1997). 5) N. D. Browning, J. P. Buban, P. D. Nellist, D. P. Norton, M. F. Chisholm, and S. J. Pennycook, Physica C, 294, 183 (1998). 6) B. H. Moeckly, D. K. Lathrop, and R. A. Buhrman, Phys. Rev. B, 47, 400 (1993). 7) E. A. Early, R. L. Steiner, A. F. Clark, and K. Char, Phys. Rev. B, 50, 9409 (1994). 8) J. Elly, M. G. Medici, A. Gilabert, F. Schmidl, P. Siedel, A. Hoffmann, and Ivan K. Schuller, Phys. Rev. B, 56, R8507 (1997). 9) I-Fei Tsu, Jyh-Lih Wang, D. L. Kaiser, and S. E. Babcock, Physica C, 306, 163 (1998). 10) R. Dimos, P. Chaudhari, and J. Mannhart, Phys. Rev. B, 41, 4038 (1990). 11) M. F. Chisholm and J. Pennycook, Nature (London), 351, 47 (1991). 12) M. B. Field, D. C. Larbalestier, A. Parikh, and K. Salama, Physica C, 280, 221 (1997). 13) O. M. Froehlich, H. Schulze, A. Beck, B. Mayer, L. Alff, R. Gross, and R. P. Huebener, Appl. Phys. Lett., 66, 2289 (1995). 14) O. Nesher and E. N. Ribak, Appl. Phys. Lett., 71, 1249 (1997). 15) R. Fehrenbacher, V. B. Geshkenbein, and Gianni Blatter, Phys. Rev. B, 45, 5450 (1992). 16) R. Gross, P. Chaudhari, M. Kawasaki, and A. Gupta, Phys. Rev. B, 42, 10 735 (1990). 17) M. Kawasaki, P. Chaudhari, and A. Gupta, Phys. Rev. Lett., 68, 1065 (1992). 18) A. Schmehl, B. Goetz, R. R. Schulz, C. W. Schneider, H. Bielefeldt, H. Hilgenkamp, and J. Mannhart, Europhys. Lett., 47, 110 (1999). 19) C. W. Schneider, R. R. Schulz, B. Goetz, A. Schmehl, H. Bielefeldt, H. Hilgenkamp, and J. Mannhart, Appl. Phys. Lett., 75, 850 (1999). 20) F. Tafuri, S. Shoklor, B. Nadgorry, M. Gurvitch, F. Lombardi, and A. Di Chiara, Appl. Phys. Lett., 71, 125 (1997). --- F. Tafuri, B. Nadgony, S. Shoklor, M. Gurvitch, F. Lombardi, F. Carillo, A. Di Chiara, and E. Sarnelli, Phys. Rev. B, 57, 14 076 (1998). 21) E. M. Jackson, B. D. Weaver, and G. P. Summers, Appl. Phys. Lett., 71, 273 (1997). 22) U. Poppe, N. Klein, U. Dahne, H. Soltner, C. L. Jia, B. Kabius, K. Urban, A. Lubig, K. Schmidt, S. Henger, S. Orbach, S. Müller, and H. Piel, J. Appl. Phys., 71, 5572 (1995). 23) T. Amien, L. Shultz, B. Kabius, and K. Urban, Phys. Rev. B, 51, 6792 (1995). 24) V. Ambegaokar and B. L. Halperin, Phys. Rev. Lett., 22, 1364 (1969). 25) R. Gross, P. Chaudhari, D. Dimos, A. Gupta, and G. Koren, Phys. Rev. Lett., 64, 228 (1990). 26) Peter A. Rosenthal, M. R. Beasley, K. Char, M. S. Colclough, and G. Zaharchuk, Appl. Phys. Lett., 59, 3482 (1991). 27) Y. M. Zhang, D. Winkler, P. A. Nilsson, and T. Claeson, Phys. Rev. B, 51, 8684 (1995). 28) A. Barone and G. Paterno, Physics and Applications of the Josephson Effect (Wiley, New York, 1982). 29) D. Winkler, Y. M. Zhang, P. A. Nilaaon, E. A. Stepantsov, and T. Claeson, Phys. Rev. Lett., 72, 1260 (1994). 30) M. D. Fiske, Rev. Mod. Phys., 36, 221 (1964). 31) T. J. Rajeevakumar, Appl. Phys. Lett., 39, 439 (1981). 32) H. Hilgenkamp, J. Mannhart, and B. Mayer, Phys. Rev. B, 53, 14 586 (1996). 33) S. K. Tolpygo and M. Gurvitch, Appl. Phys. Lett., 69, 3914 (1996). 34) J. Humlicek, J. Kircher, H. U. Habermeier, M. Cardona, and A. Roseler, Physica C, 190, 383 (1992). 35) J. W. Seo, B. Kabius, U. Dähne, A. Scholen, and K. Urban, Physica C, 245, 25 (1995). 36) Tokushi Kizuka, Motoaki Iijima, and Nobuo Tanaka, Philos. Mag. A, 77, 413 (1998).