Jpn. J. Appl. Phys. 44 (2005) pp. L1525-L1528 |Previous Article| |Next Article| |Table of Contents|
|Full Text PDF (163K)| |Buy This Article|
Possible Breakthrough for Higher Tc Discovered in Bi(Pb)2223 Practical Tapes
Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
1Sumitomo Electric Industries, Ltd., 1-1-3 Shimaya, Konohana-ku, Osaka 554-0024, Japan
(Received September 29, 2005; accepted October 22, 2005; published December 2, 2005)
By systematic studies on the post-annealing effect in air for Bi(Pb)2223 practical tapes, Tc(onset) was found to be enhanced up to 115.2 K by annealing at 680°C for 250 h from 110.2 K for an as-synthesized tape. Annealing at ∼700°C for a long time always increased the Tc(onset) of the tape above 114 K, at which the generation of the Pb3221 phase simultaneously occurred during annealing. The slightly increased c-axis length was confirmed for annealed samples. The compositional change of cations in Bi(Pb)2223 during post-annealing is believed to be responsible for the Tc enhancement of the present system.
- K. Sato, T. Hikata, H. Mukai, M. Ueyama, N. Shibuta, Y. Kato, T. Masuda, M. Nagata, K. Iwata and T. Mitsui: IEEE Trans. Magn. 27 (1991) 1231.
- For example, U. Endo, S. Koyama and T. Kawai:
Jpn. J. Appl. Phys. 27 (1988) L1476[JSAP].
- T. Kaneko, H. Yamauchi and S. Tanaka:
Physica C 178 (1991) 377[CrossRef].
- A. Schilling, M. Cantoni, J. D. Guo and H. R. Ott:
Nature 363 (1993) 56[CrossRef].
- J. Wang, M. Wakata, T. Kaneko, S. Takano and H. Yamauchi:
Physica C 208 (1993) 323[CrossRef].
- W. G. Wang, J. Horvat, J. N. Li, H. K. Liu and S. X. Dou:
Physica C 297 (1998) 1[CrossRef].
- K. Yamazaki, T. Kato, K. Ohkura, M. Ueyama, N. Ayai, H. Takigawa, E. Ueno, K. Hayashi and K. Sato: Trans. Mater. Res. Soc. Jpn. 29 (2004) 1229.
- S. Kobayashi, T. Kato, K. Yamazaki, K. Ohkura, K. Fujino, J. Fujikami, E. Ueno, N. Ayai, M. Kikuchi, K. Hayashi, K. Sato and R. Hata:
IEEE Trans. Appl. Supercond. 15 (2005) 2534[CrossRef].