The Bi-2223 Superconducting Wires With 200A-Class Critical Current

• Published in: IEEE transactions on applied superconductivity 2007-06, Vol.17 (2), p.3075-3078
• Main Authors: Ayai, N., Kikuchi, M., Yamazaki, K., Kobayashi, S., Yamade, S., Ueno, E., Fujikami, N.J., Kato, T., Hayashi, K., Sato, K., Hata, R., Iihara, J., Yamaguchi, K.J., Shimoyama, J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bismuth; COPPER OXIDE; Critical current; Critical current (superconductivity); Critical current density; CURRENT DENSITY; DENSITY; Electric potential; Electric wire; Electrical engineering. Electrical power engineering; Electronics; Exact sciences and technology; Filaments; Heat treatment; High temperature superconductors; Manufacturing; Materials; Mechanical factors; MECHANICAL PROPERTIES; Nitrogen; Powders; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SINTERING; Superconducting devices; Superconducting filaments and wires; Superconducting tapes; SUPERCONDUCTIVITY; SUPERCONDUCTORS; TAPE; WIRE
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2007.897947

Critical current of a silver-sheathed Bi-2223 tape using controlled-overpressure sintering has attained 201 A, which is equivalent to 493 A per 10 mm-width. The engineering current density is 21kA/cm 2 , while the critical current density on the total filaments area is 56 . Critical currents are also improved noticeably at low temperatures and high magnetic fields normal to the tape plane. Typical critical currents have reached 500 A at 4.2 K in 5 T and 200 A at 20 K in 10 T. The highest critical currents of long wires currently have reached 195 A for 70 m and 191 A for 178 m. The wires with 200 A-class critical current are similar in mechanical properties to 150 A-class long wires commercially produced by Sumitomo Electric using the controlled-overpressure sintering. The microstructure study has predicted far higher potential of critical current, according to the confirmed remaining issues on the 200 A-class tapes; incomplete orientation order, aggregation of alkaline earth cuprates and inter-granular Bi-2212.