Critical current characteristics in MgB2 bulks

✍ Scribed by M. Kiuchi; H. Mihara; K. Kimura; T. Haraguchi; E.S. Otabe; T. Matsushita; A. Yamamoto; J. Shimoyama; K. Kishio

• Book ID: 104082602
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 137 KB
• Volume: 445-448
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2006.04.039

✦ Synopsis

The effects of low temperature sintering and C-doping on the critical current density of MgB 2 superconductor was investigated and the obtained results were compared with the theoretical results of the flux creep-flow model. The critical current density increased by these treatments over a wide range of magnetic fields. It is proposed that the improvement of the critical current density at low magnetic fields comes from the reduction of the grain size in the specimen sintered at low temperatures and from the increase in the elementary pinning force of grain boundaries in the C-doped specimens. On the other hand, the improvement of the critical current density at high fields is mainly caused by the enhancement of the upper critical field due to the electron scattering by grain boundaries and C atoms.