Large single-grain RE-Ba-Cu-O (RE: rare-earth elements) superconductors can trap large magnetic fields over several tesla, and thus can be used as quasi-permanent magnets, generating fields much higher than those of conventional permanent magnets. However, the maximum trapped field is essentially limited by the mechanical properties of bulk superconductors, since a large electromagnetic force acts on the bulks when they trap large fields. The stress produced by refrigeration also causes cracking. We have recently found that epoxy resin can penetrate into bulk superconductors under appropriate conditions. Microstructural observations revealed that microcracks as well as macrocracks or porosities can be impregnated with epoxy resin, which greatly improves the mechanical properties of bulk RE-Ba-Cu-O superconductors and thus results in the improvement of their field-trapping capability.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy (miscellaneous)
- Condensed Matter Physics