A Trapped Field of >3T in Bulk MgB2 Fabricated by Uniaxial Hot Pressing
arXiv:1207.6982 · doi:10.1088/0953-2048/25/11/112002
Abstract
A trapped field of over 3 T has been measured at 17.5 K in a magnetised stack of two disc-shaped bulk MgB2 superconductors of diameter 25 mm and thickness 5.4 mm. The bulk MgB2 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 MgB2, 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 MgB2.
arXiv comment10 pages, 4 figures. Accepted as a Rapid Publication in Superconductor Science and Technology (Final version after peer review)
References in corpus (9)
- Strongly linked current flow in polycrystalline forms of the new superconductor MgB2
- Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SiC doping
- Improved superconducting properties in nanocrystalline bulk MgB_2
- The behavior of grain boundaries in the Fe-based superconductors
- Strong Pinning Enhancement in MgB2 Using Very Small Dy2O3 Additions
- High-pressure synthesis of MgB2 with addition of Ti
- Towards the Realization of Higher Connectivity in MgB2 Conductors: In-situ or Sintered Ex-situ?
- Temperature dependence of trapped magnetic field in MgB2 bulk superconductor
- MgB2 bulk superconducting magnet