Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-29T07:32:28.054Z Has data issue: false hasContentIssue false
  • English
  • Français

Growth and Transport Properties of Tunneling Barriers in Hts Devices

Published online by Cambridge University Press:  15 February 2011

G. J. Gerritsma ,
M. A. J. Verhoeven ,
R. Moerman ,
D. H. A. Blank  and
H. Rogalla
G. J. Gerritsma
Affiliation:
Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
M. A. J. Verhoeven
Affiliation:
Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
R. Moerman
Affiliation:
Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
D. H. A. Blank
Affiliation:
Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
H. Rogalla
Affiliation:
Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
Get access

Abstract

In this contribution we will discuss the charge transport of ramp-type HTS Josephson junctions with a Ga-doped PBCO barrier layer. It will be demonstrated that in these junctions charge transport takes place via tunneling processes. The Cooper pairs tunnel directly, at least for T ≤ Tc/2, whereas the quasiparticles tunnel indirectly via localized states. By substituting Cu-chain atoms with Ga-atoms the density of localized states appear to be reduced, resulting in an increase in IcRn-product. Another way to increase this product is a reduction in barrier thickness. Growth studies by AFM of PBCO barriers on ramps indicate that below about 10 nm barriers become increasingly less homogeneous, and below about 6 nm pin holes are very likely to occur. This sets a lower limit on the useful barrier thickness. Presently critical-current densities up to 104 A/cm2 at 40 K, and IlR,-products up to 10 mV at 4.2 K are easily obtained.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 401: Symposium G – Epitaxial Oxide Thin Films II , 1995 , 287
Copyright
Copyright © Materials Research Society 1996

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

1. Wiegerink, R.J., Gerritsma, G.J., Reuvekamp, E.M.C.M., Verhoeven, M.A.J. and Rogalla, H., IEEE Trans. Appl. Superconduct. 5, 3452 (1995).Google Scholar
2. Xu, Y., Matsuda, A., and Beasley, M.R., Phys. Rev. B 42, 1494 (1990).Google Scholar
3. Xu, Y., Ephron, D., and Beasly, M.R., Phys. Rev. B bfseries 52, 2843 (1995).Google Scholar
4. Glazman, L.I. and Matveev, K.A., Sov. Phys. JETP 67, 1276 (1988) [Zh. Eksp. Teor. Fiz. 94, 332 (1988)].Google Scholar
5. Aslamazov, L.G. and Fistul, M.V.', Sov.Phys. JETP 56, 666 (1982) [Zh. Eksp. Teor. Fiz. 83, 1170 (1982)].Google Scholar
6. Devyatov, I.A. and Kupriyanov, M.Yu., JETP Lett. 59, 200 (1994) [Pis'ma Zh. Eksp. Teor. Fiz. 59, 187 (1994)].Google Scholar
7. Deutscher, G. and Mueller, K.A., Phys. Rev. Lett. 59, 1745 (1987).Google Scholar
8. Klausmeier-Brown, M.E., Virshup, G.F., Bozovic, I., Eckstein, J.N. and Ralls, K.S., Appl. Phys. Lett. 60, 2807 (1992).Google Scholar
9. Gao, J., Aarnink, W.A.M., Gerritsma, G.J. and Rogalla, H., Physica C 171, 126 (1990).Google Scholar
10. Gavaler, J.R., Talvacchio, J., Braggings, T.T., Forrester, M.G., Greggi, J., J. Appl. Phys. 70, 4383 (1991).Google Scholar
11. Verhoeven, M.A.J., Gerritsma, G.J. and Rogalla, H., IEEE Trans. Appl. Supercond. 5, 2095 (1995).Google Scholar
12. Sodtke, E., Andrzejak, C., Guggi, D., Xu, Y, Phycica C 180, 50 (1991).Google Scholar
13. Fisher, B., Koren, G., Genossar, J., Patlagan, L. and Gartstein, E.L., Physica C 176, 75 (1991).Google Scholar
14. Verhoeven, M.A.J., Gerritsma, G.J. and Rogalla, H., IEEE Trans. Appl. Superconduct. 5, 2095 (1995).Google Scholar
15. Takenaka, K., Imanaka, Y., Tamasaku, K., Itoh, T., and Uchida, S., Phys. Rev. B 46, 5833 (1992).Google Scholar
16. Fehrenbacher, R. and Rice, T.M., Phys. Rev. Lett. 70, 347 (1991).Google Scholar
17. Lichtenstein, A.I and Mazin, I.I., Phys. Rev. Lett. 74, 1000 (1995).Google Scholar
18. Mary, T.A., Kumar, N.R.S., and Varadaraju, U.V., J. Solid State Chem. 107, 524 (1993).Google Scholar