Abstract
Gold (Au) and silver (Ag) are known to be important contact metals on YBa2Cu3O7−x (YBCO). Both metals have been used as additives in fabricating tapes of YBCO and Bi2Sr2CaCu2O8 (BSCCO) materials, and have favorable results in improving not only the flexibility but also the weighted critical currents of the resulting composites. Previous results on superconductor/normal metal/superconductor junctions made using YBCO/Au/YBCO and YBCO/Au/Nb demonstrated that a supercurrent can be induced in the normal metal layers through the proximity effect. Our transmission electron microscopy study of the Au/YBCO interfaces shows a well-bonded interface with no extraneous phases present. Lattice fringes of the (001) plane in YBCO terminated at the interface abruptly. This observation supports previous results of contact resistance of x-ray photoelectron spectroscopy (XPS). Both (001) integral steps and multiples of 1/3 (001) steps were observed at the Au/YBCO interface. When the top gold layer was absent locally, surface degradation was observed as the (001) lattice fringes stopped short from the surface by 10 nm. Our results support that Au is a desirable contact metal and a dependable surface passivation material for YBCO.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Q. Y. Ma, M. T. Schmidt, L. S. Weinman, E. S. Yang, S. M. Sampere, and S-W. Chan, J. Vacuum Sci. Technol. A 9, 390 (1991).
K. Heine, J. Tenbrink, and M. Thoener, Appl. Phys. Lett. 55, 2441–2443 (1989).
K. Osamura, T. Takayama, and S. Ochial, Supercond. Sci. Technol. 2, 107 (1989).
M. Murakami, in Studies of High Temperature Superconductors, edited by A. V. Narikar (Nova Science Publishers, Tokyo, 1991).
L. J. Masur, E. R. Podtburg, C. A. Craven, A. Otto, Z. L. Wang, D. M. Kroeger, J. Y. Coulter, and M. P. Maley, Physica C 230, 274 (1994).
Y. Tzeng, A. Holt, and R. Ely, Appl. Phys. Lett. 52, 155 (1988); J. W. Ekin, A. J. Panson, and B. A. Blankenship, Appl Phys. Lett. 52, 331 (1988); J. W. Ekin, T. M. Larson, N. F. Bergen, A. J. Nelson, A. B. Swartzlander, L. L. Kazmerski, A. J. Panson, and B. A. Blankenship, Appl. Phys. Lett. 52, 1819 (1988).
D. L. Kaiser, F. Holtzberg, M. F. Chisholm, and T. K. Worthington, J. Cryst. Growth 85, 593 (1987).
P. M. Mankiewich, D. B. Schwartz, R. E. Howard, L. D. Jackel, B. L. Straughn, E. G. Burkhardt, and A. H. Dayem, 5th Int. Workshop on Future Electron Devices—High Temperature Superconducting Electron Devices-(FED HiTcSc-ED WORKSHOP), June 2–4, 1988, MIyagi-ZAo, pp. 157–160; P. M. Mankiewich et al., IEEE Magn. 25 (1990); L. H. Greene, J. B. Barner, W. L. Feldmann, L. A. Farrow, P. F. Miceli, R. Ramesh, B. J. Wilkens, B. G. Bagley, J. M. Tarascon, J. H. Wernick, M. Giroud, and J. M. Rowell, Physica C 162–164, 1573 (1989); R. H. Ono, J. A. Beall, M. W. Cromar, T. E. Harvey, M. E. Johansson, C. D. Reintsema, and D. A. Rudman, Appl. Phys. Lett. 59, 1126 (1991).
Q. Li, D. B. Fenner, W. D. Hamblen, and D. G. Hamblen, Appl. Phys. Lett. 62, 2428 (1993); D. B. Fenner, Q. Li, W. D. Hamblen, M. E. Johansson, D. G. Hamblen, L. Lynds, and J. I. Budnick, IEEE Trans. Appl. Supercon. 3, 2104 (1993).
S-W. Chan, D. M. Hwang, and L. Nazar, J. Appl. Phys. 65, 4719 (1989).
Y. Feng, D. C. Larbalestier, S. E. Babcock, and J. B. Vander Sande, Appl. Phys. Lett. 61, 1234 (1992).
S-W. Chan, J. Phys. Chem. Solids 55, 1415 (1994).
A. F. Marshall and R. Ramesh, in Interfaces in High-Tc Superconducting Systems, edited by S. L. Shinde and D. A. Rudman (Springer-Verlag, New York, 1994), p. 71.
V. Pendrick, R. Brown, J. R. Matey, A. Findikoglu, X. X. Xi, T. Venkatesan, and A. Inam, J. Appl. Phys. 69, 7927 (1991).
J. W. Ekin, S. E. Russek, C. C. Clickner, and B. Jeanneret, Appl. Phys. Lett. 62, 369 (1993).
Contact resistivity1 of Au/YBCO interfaces from an ex situ process was reported to be 8.6 × 10−3 Ω cm2 at 300 K and 4.9 × 10−5 Ω cm2 at 77 K, while a lower value13 of 2.6 × 10−7 Ω cm2 at 79 K with oxygen anneal from an ex situ process and even a lower contact resistivity14 in the range of 10−8−10−9 Ω cm2 at 4 K from an in situ process without oxygen anneal had been reported.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chan, SW., Zhao, L., Chen, C. et al. Interface between gold and superconducting YBa2Cu3O7−x. Journal of Materials Research 10, 2428–2432 (1995). https://doi.org/10.1557/JMR.1995.2428
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/JMR.1995.2428