RE-Ba-Cu-O for high functional superconducting permanent magnet

Among various potential applications of melt-textured RE-Ba-Cu-O (REBCO, RE: rare earth elements) superconductors, we have examined the bulk application as the superconducting permanent magnet, especially for the magnetically-levitated (MAGLEV) train. Compared with Y-Ba-Cu-0 (YBCO), oxygen-controlled melt-growth (OCMG)-processed LREBCO (LRE: light rare earth elements) bulk superconductors are more promising for this application because of larger critical current density (Jc) values in high field and higher irreversibility field (Birr) within the range of the liquid nitrogen refrigeration (63–77 K), implying that even higher trapped fields (Bt) are achievable in principle. In this paper, material requirements of superconducting bulks for the MAGLEV train are first presented and then processing aspects for the fabrication of good LREBCO bulks are described.