A trapped field of > 3 T in bulk MgB2 fabricated by uniaxial hot pressing

Journal article

A trapped field of over 3T has been measured at 17.5K in a magnetized stack of two disc-shaped bulk MgB superconductors of diameter 25mm and thickness 5.4mm. The bulk MgB samples were fabricated by uniaxial hot pressing, which is a readily scalable, industrial technique, to 91% of their maximum theoretical density. The macroscopic critical current density derived from the trapped field data using the Biot-Savart law is consistent with the measured local critical current density. From this we conclude that critical current density, and therefore trapped field performance, is limited by the flux pinning available in MgB, rather than by lack of connectivity. This suggests strongly that both increasing sample size and enhancing pinning through doping will allow further increases in trapped field performance of bulk MgB.

Authors: Durrell, J; Dancer, C; Dennis, A; Shi, Y; Xu, Z

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Superconductor Science and Technology
• Volume: 25
• Issue: 11
• Pages: 112002-112002
• Publication date: 2012-11-01
• DOI: 10.1088/0953-2048/25/11/112002
• EISSN: 1361-6668
• ISSN: 0953-2048