Abstract
Large-grain high-temperature superconductors of the form RE-Ba-Cu-O (where RE is a rare-earth element) can trap magnetic fields of several tesla at low temperatures, and so can be used for permanent magnet applications1,2. The magnitude of the trapped field is proportional to the critical current density and the volume of the superconductor3,4. Various potential engineering applications for such magnets have emerged5,6,7,8,9,10,11,12,13, and some have already been commercialized7,8,9,10. However, the range of applications is limited by poor mechanical stability and low thermal conductivity of the bulk superconductors14,15,16,17; RE-Ba-Cu-O magnets have been found to fracture during high-field activation, owing to magnetic pressure14,15,16. Here we present a post-fabrication treatment that improves the mechanical properties as well as thermal conductivity of a bulk Y-Ba-Cu-O magnet, thereby increasing its field-trapping capacity. First, resin impregnation and wrapping the materials in carbon fibre improves the mechanical properties. Second, a small hole drilled into the centre of the magnet allows impregnation of Bi-Pb-Sn-Cd alloy into the superconductor and inclusion of an aluminium wire support, which results in a significant enhancement of thermal stability and internal mechanical strength. As a result, 17.24 T could be trapped, without fracturing, in a bulk Y-Ba-Cu-O sample of 2.65 cm diameter at 29 K.
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References
Nariki, S., Sakai, N. & Murakami, M. Processing of high-performance Gd-Ba-Cu-O bulk superconductor with Ag addition. Supercond. Sci. Technol. 15, 648–652 (2002)
Ikuta, H. et al. Melt-processed Sm-Ba-Cu-O superconductors trapping strong magnetic field. Supercond. Sci. Technol. 11, 1345–1347 (1998)
Murakami, M. Melt Processed High Temperature Superconductors (World Scientific, Singapore, 1991)
Cardwell, D. A. Processing and properties of large grain (RE)BCO. Mater. Sci. Eng. B 53, 1–10 (1998)
Weinberger, B. R., Lynds, L., Hull, J. R. & Balachandran, U. Low friction in high temperature superconductor bearings. Appl. Phys. Lett. 59, 1132–1134 (1991)
Matsunaga, M. et al. YBCO bulk for the superconducting bearing for a 10kWh flywheel. Supercond. Sci. Technol. 15, 842–845 (2002)
Minami, H. & Yuyama, J. Construction and performance test of a magnetically levitated transport system in vacuum using high-Tc superconductors. Jpn J. Appl. Phys. 34, 346–349 (1995)
Kovalev, L. K. et al. High output power reluctance electric motors with bulk high-temperature superconductor elements. Supercond. Sci. Technol. 15, 817–822 (2002)
Oka, T. et al. Construction of 2-5 T class superconducting magnetic field generator with use of an Sm123 bulk superconductor and its application to high-magnetic field demanding devices. Physica C 335, 101–106 (2000)
Saho, N., Mizumori, T., Nishijima, N., Murakami, M. & Tomita, M. High-Tc bulk-superconductor based membrane-magnetic separation for water purification. J. Am. Ceram. Soc. (in the press)
Mizutani, U. et al. Application of RE123-bulk superconductors as a permanent magnet in magnetron sputtering film deposition apparatus. J. Am. Ceram. Soc. (in the press)
Yoo, S. I., Higuchi, T., Sakai, N., Fujimoto, H. & Murakami, M. RE-Ba-Cu-O for high functional superconducting permanent magnet. Mater. Sci. Eng. B 52, 203–210 (1998)
Wang, J. et al. A scheme of maglev vehicle using high Tc bulk superconductors. IEEE Trans. Appl. Supercond. 9, 904–907 (1999)
Ren, Y., Weinstein, R., Liu, J., Sawh, R. P. & Foster, C. Damage caused by magnetic pressure at high trapped field in quasi-permanent magnets composed of melt-textured Y-Ba-Cu-O superconductor. Physica C 251, 15–26 (1995)
Gao, L., Xue, Y., Meng, L. & Chu, C. W. Thermal instability, magnetic shielding and trapping in single-grain YBa2Cu3O7-δ bulk materials. Appl. Phys. Lett. 64, 520–522 (1994)
Fuchs, G. et al. Trapped magnetic fields larger than 14T in bulk YBa2Cu3O7-x . Appl. Phys. Lett. 76, 2107–2109 (2000)
Johansen, T. H. Flux-pinning-induced stress and strain in superconductors: Case of a long circular cylinder. Phys. Rev. B 60, 9690–9713 (1999)
Diko, P. Thermal stresses and microcracking caused by 211 particles in Y-Ba-Cu-O melt-processed bulks. Mater. Sci. Eng. B 53, 149–153 (1998)
Sakai, N., Ishihara, D., Inoue, I. & Murakami, M. Formation of pores in melt-processed RE-Ba-Cu-O and the techniques to reduce pore density. Supercond. Sci. Technol. 15, 698–701 (2002)
Sakai, N., Seo, S. J., Inoue, K., Miyamoto, T. & Murakami, M. in Advances in Superconductivity XI (eds Koshizuka, N. & Tajima, S.) 685–688 (Springer, Tokyo, 1999)
Collings, E. W. & Sumption, M. D. in Advances in Superconductivity VII (eds Yamafuji, K. & Morishita, T.) 605–608 (Springer, Tokyo, 1995)
Yeh, F. & White, K. W. Fracture toughness behavior of the YBa2Cu3O7-x superconducting ceramic with silver oxide additions. J. Appl. Phys. 70, 4989–4994 (1991)
Morita, M. et al. Trapped field and mechanical properties of QMG magnet. Proc. 1988 Int. Workshop on Superconductivity 115–118 (ISTEC, Tokyo, 1998)
Tomita, M. & Murakami, M. Improvement of the mechanical properties of bulk superconductors with resin impregnation. Supercond. Sci. Technol. 13, 722–724 (2000)
Tomita, M., Murakami, M. & Katagiri, K. Reliability of mechanical properties for bulk superconductors with resin impregnation. Physica C 378-381, 783–787 (2002)
Salama, K. et al. Recent developments in melt-textured superconductors. JOM 17–28 (June 2000)
Iwasa, Y. Case Studies in Superconducting Magnets (Plenum, New York, 1994)
Acknowledgements
We thank K. Itoh and H. Wada for use of an 18-T superconducting magnet. This work was partially supported by NEDO as Collaborative Research and Development of Fundamental Technologies for Superconductivity Applications.
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Tomita, M., Murakami, M. High-temperature superconductor bulk magnets that can trap magnetic fields of over 17 tesla at 29 K. Nature 421, 517–520 (2003). https://doi.org/10.1038/nature01350
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DOI: https://doi.org/10.1038/nature01350
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