High critical current density and enhanced irreversibility field in superconducting MgB2 thin films
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- 31 May 2001
- journal article
- research article
- Published by Springer Nature in Nature
- Vol. 411 (6837), 558-560
- https://doi.org/10.1038/35079018
Abstract
The discovery of superconductivity at 39 K in magnesium diboride1 offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. This compound has twice the transition temperature of Nb3Sn and four times that of Nb-Ti alloy, and the vital prerequisite of strongly linked current flow has already been demonstrated2,3,4,5. One possible drawback, however, is that the magnetic field at which superconductivity is destroyed is modest. Furthermore, the field which limits the range of practical applications—the irreversibility field H*(T)—is approximately 7 T at liquid helium temperature (4.2 K), significantly lower than about 10 T for Nb-Ti (ref. 6) and ∼20 T for Nb3Sn (ref. 7). Here we show that MgB2 thin films that are alloyed with oxygen can exhibit a much steeper temperature dependence of H*(T) than is observed in bulk materials, yielding an H* value at 4.2 K greater than 14 T. In addition, very high critical current densities at 4.2 K are achieved: 1 MA cm-2 at 1 T and 105 A cm-2 at 10 T. These results demonstrate that MgB2 has potential for high-field superconducting applications.Keywords
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This publication has 15 references indexed in Scilit:
- The upper critical field in superconducting MgB2Journal of Alloys and Compounds, 2001
- Specific heat in the superconducting and normal state (2–300 K, 0–16 T), and magnetic susceptibility of the 38 K superconductor MgB2: evidence for a multicomponent gapPhysica C: Superconductivity and its Applications, 2001
- Superconducting properties of MgB2 bulk materials prepared by high-pressure sinteringApplied Physics Letters, 2001
- Superconductivity in DenseWiresPhysical Review Letters, 2001
- Thermodynamic and Transport Properties of SuperconductingPhysical Review Letters, 2001
- Boron Isotope Effect in SuperconductingPhysical Review Letters, 2001
- Anisotropic flux pinning in a network of planar defectsPhysical Review B, 1994
- The role of grain boundaries in determining J c in high-field high-current superconductorsPhilosophical Magazine Part B, 1987
- Critical fields, Pauli paramagnetic limiting, and material parameters ofSn andSiPhysical Review B, 1979
- Flux vortices and transport currents in type II superconductorsAdvances in Physics, 1972