Permanent magnet with MgB{sub 2} bulk superconductor

Journal Article · Mon Jul 21 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4890724· OSTI ID:22311152

Yamamoto, Akiyasu ^[1]; Ishihara, Atsushi; Tomita, Masaru ^[2]; Kishio, Kohji ^[1]

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1. The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)
2. Railway Technical Research Institute, 2-8-38 Hikari, Kokubunji, Tokyo 185-8540 (Japan)

Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulk magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.

• OSTI ID: 22311152
• Journal Information: Applied Physics Letters, Vol. 105, Issue 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON COMPOUNDS
CURRENTS
HIGH-TC SUPERCONDUCTORS
HYSTERESIS
IRON COMPOUNDS
MAGNESIUM BORIDES
MAGNETIC FIELDS
MONOCRYSTALS
NEODYMIUM COMPOUNDS
NMR IMAGING
PERMANENT MAGNETS
POLYCRYSTALS
SHORTAGES
STABILITY
TEMPERATURE RANGE 0013-0065 K
TRAPPING