Improving the critical current density in Bi-2223 wires via a reduction of the secondary phase content

• Published in: IEEE transactions on applied superconductivity 2003-06, Vol.13 (2), p.3038-3041
• Main Authors: Huang, Y.B., Cai, X.Y., Holesinger, T., Maroni, V.A., Yu, D., Parrella, R., Rupich, M., Hellstrom, E., Teplitsky, M., Venkataraman, K., Otto, A., Larbalestier, D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bi-based cuprates; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical current; Critical current density; Cuprates superconductors (high tc and insulating parent compounds); Current measurement; Density measurement; Electrical engineering. Electrical power engineering; Exact sciences and technology; Materials; Measurement standards; Microstructure; Multifilamentary superconductors; Physics; Size measurement; Superconducting filaments and wires; Superconducting films; Superconductivity
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2003.812067

Progress in the performance of multifilamentary composite Bi-2223 wire fabricated at American Superconductor is reviewed. Critical current (I/sub c/) performance of 175 A at 77 K and self-field and critical current density (J/sub c/) performance of 22.1 kA/cm/sup 2/ (77 K, 0.1 T perpendicular to the tape plane) have been measured for short samples of Bi-2223 wire (standard size is 0.21/spl times/4.0/spl times/100 mm). Microstructure analysis by SQUID magnetometry, transmission XRD and TEM shows a large amount of residual 2212 intergrowth remaining in Bi-2223 grains. Residual 2212 intergrowth is seen to correlate with self-field J/sub c/ at 77 K across a range of experimental samples, suggesting that higher levels of performance will be achieved by further reducing residual 2212.