1. Critical flux pinning and enhanced upper-critical-field in magnesium diboride films
- Author
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Kunchur, M. N., Wu, C., Arcos, D. H., Ivlev, B. I., Choi, Eun-Mi, Kim, Kijoon H. P., Kang, W. N., and Lee, Sung-Ik
- Subjects
Condensed Matter - Superconductivity - Abstract
We have conducted pulsed transport measurements on c-axis oriented magnesium diboride films over the entire relevant ranges of magnetic field $0 \alt H \alt H_{c2}$ (where \hcu is the upper critical field) and current density $0 \alt j \alt j_{d}$ (where $j_{d}$ 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 six-fold enhancement of $H_{c2}$ and raises the depinning current density $j_{c}$ to within an order of magnitude of $j_{d}$. The current-voltage response is highly non-linear at all fields, resulting from a combination of depinning and pair-breaking, and has no trace of an Ohmic free-flux-flow regime. Keywords: pair, breaking, depairing, superconductor, superconductivity, flux, fluxon, vortex, mgb2
- Published
- 2003
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