2003/09/12 by Milind N. Kunchur, M. N. Kunchur, Cheng Wu +11
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.68.100503
published as Phys. Rev. B 68, 100503 (2003)
openalex publication_date 2003/09/12 · arxiv created 2003/11/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have conducted pulsed transport measurements on c-axis-oriented magnesium diboride films over the entire relevant ranges of magnetic field 0\ensuremath\lesssimH\ensuremath\lesssimHc2 (where Hc2 is the upper critical field) and current density 0\ensuremath\lesssimj\ensuremath\lesssimjd (where jd\ensuremath∼107A/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\ifmmode±\else\textpm\fi3T) 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.