Abstract
The transport critical current density Jc is one of the most important properties for practical applications of high-Tc superconductors. The Jc properties of high-Tc superconductors are highly dependent on the microstructural texturing of the superconducting phase. In order to improve the grain alignment of the superconducting phase melt-processing in high magnetic fields is a very effective method based on the anisotropy of magnetic susceptibility. For Bi-based superconducting bulks and tapes, there have been many studies using the in-field melt-processing and large J2 enhancements due to the texture improvement are observed. In this study, we employed melt-processing in high magnetic fields for the Ag/Bi2212 round wires, which are much superior to thin tapes in fabricating superconducting magnets. Since the Jc properties of Ag/Bi2212 are very sensitive to the maximum temperature of the heat treatment, we performed the melt-processing under various maximum processing temperatures. During the heat treatment, a magnetic field of 0 T or 5 T was applied using a cryocooled superconducting magnet. For the wires heat-treated under a magnetic field, small increase of the Jc values were observed. From the results of the detailed analysis of the E - J properties, we found that there are possible microstructural changes due to the in-field process. It is suggested that the in-field heat-treatment is very effective for not only Jc enhancement but also the n-value improvement for Bi2212 conductors.
Original language | English |
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Pages (from-to) | 3106-3108 |
Number of pages | 3 |
Journal | IEEE Transactions on Applied Superconductivity |
Volume | 17 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2007 Jun |
Keywords
- Bismuth compound
- Magnetic field effects
- Superconducting filaments and wires
- Superconducting materials growth
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering