abstract

• We have conducted pulsed transport measurements on c-axis-oriented magnesium diboride films over the entire relevant ranges of magnetic field 0≲H≲Hc2 (where Hc2 is the upper critical field) and current density 0≲j≲jd (where jd∼107 A/cm2 is the depairing current density). The intrinsic disorder of the films combined with the large coherence length and three dimensionality, compared to cuprate superconductors, results in a sixfold enhancement of Hc2 (to 17 ± 3T) and raises the depinning current density jc to within an order of magnitude of jd. The current-voltage response has an unusually steep nonlinear shape at all fields, resulting from a combination of depinning and pair breaking, and has no trace of an Ohmic free-flux-flow regime. © 2003 The American Physical Society.

authors

• Arcos H.
• Choi E.-M.
• Ivlev Boris
• Kang N.
• Kim H.P.
• Kunchur M.N.
• Lee S.-I.
• Wu C.

publication date

• 2003-01-01

published in

• Physical Review B - Condensed Matter and Materials Physics  Journal

keywords

• boron derivative; magnesium derivative; article; conductor; film; magnetic field; mathematical analysis; measurement; temperature dependence

Digital Object Identifier (DOI)

• 10.1103/PhysRevB.68.100503

start page

end page

volume

• 68

issue

• 10