Surface nucleation in a superconductor coated with a normal metal

2005

Phys. Rev. B

(2005) 'Numerical studies on the e ect of normal-metal coatings on the magnetization characteristics of type-II superconductors. ', Physical review B., 71 (14). p. 144507.Further information on publisher's website: Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Magnetic properties of superconductors coated with metals of arbitrary resistivity N are calculated using the time-dependent Ginzburg-Landau equations in which both T c and N vary. As N in the coating is reduced, the initial vortex penetration field H p ͑ N ͒ does not decrease monotonically from the insulating ͑Matricon͒ limit to the extreme metallic ͑Bean-Livingston͒ limit, but has a minimum value H p͑min͒ below the extreme metallic value. The minimum occurs because the barrier is weakened by proximity-effect penetration of superelectrons into the coating which only occurs at finite resistivity. In an applied magnetic field, local depressions in nucleate in the coating which do not have the well-known quantum of magnetic flux ͑h /2e͒ until they have crossed the coating and entered the interior of the superconductor. When T = 0 and T c of the normal metal coating is zero, the minimum vortex penetration field H p͑min͒ Ϸ 0.76 −1.17 H c2 which occurs for a coating resistivity N Ϸ 1.1 −0.6 S . For T Ͼ 0 the minimum is attenuated. Adding a thick weakly superconducting SЈ layer between the superconductor and normal metal coating reduces the irreversibility markedly.

Section: A Flux Entry Behaviormentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Numerical studies on the effect of normal-metal coatings on the magnetization characteristics of type-II superconductors

Carty

Machida²,

2005

Phys. Rev. B

“…Whether the mechanism causing the superconductivity is BCS-like or not, GinzburgLandau (GL) theory [4] shows that in the vicinity of a superconducting-insulating barrier, B C2 is increased. Hence, there is strong evidence that increasing disorder, either by increasing N or from reduced-size effects, increases B C2 [5].…”

mentioning

confidence: 99%

Disordered Nanocrystalline SuperconductingPbMo6S8with a Very Large Upper Critical Field

Niu

2003

Phys. Rev. Lett.

Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

“…We define DN x to be an imaginary quantity so that the equations have the same form in both the superconductor and the normal metal, contrary to the usual convention 16,17 in which can be ignored and a simple analytic solution is possible 2,16 . In zero-field, the field term can also be ignored so equation (5) (13) In the thick junction limit of …”

Section: General Considerationsmentioning

confidence: 99%

The critical current density of an SNS Josephson-junction in high magnetic fields

Carty

Supercond. Sci. Technol.

2013

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.