Dramatic role of critical current anisotropy on flux avalanches in MgB2 films
arXiv:cond-mat/0607063 · doi:10.1103/PhysRevLett.98.117001
Abstract
Anisotropic penetration of magnetic flux in MgB2 films grown on vicinal sapphire substrates is investigated using magneto-optical imaging. Regular penetration above 10 K proceeds more easily along the substrate surface steps, anisotropy of the critical current being 6%. At lower temperatures the penetration occurs via abrupt dendritic avalanches that preferentially propagate {\em perpendicular} to the surface steps. This inverse anisotropy in the penetration pattern becomes dramatic very close to 10 K where all flux avalanches propagate in the strongest-pinning direction. The observed behavior is fully explained using a thermomagnetic model of the dendritic instability.
arXiv comment4 pages, 5 figures
References in corpus (7)
- Experiments in vortex avalanches
- Dendritic magnetic instability in superconducting MgB2 films
- Dendritic and uniform flux jumps in superconducting films
- Dendritic flux avalanches and nonlocal electrodynamics in thin superconducting films
- Onset of dendritic flux avalanches in superconducting films
- Superconducting MgB2 thin films by pulsed laser deposition
- Avalanche-driven fractal flux distributions in NbN superconducting films
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- Oscillatory regimes of the thermomagnetic instability in superconducting films
- The thermomagnetic instability in superconducting films with adjacent metal layer
- Impact of border defects on the magnetic flux penetration in superconducting films
- Active control of thermomagnetic avalanches in superconducting Nb films with tunable anisotropy
- Magnetic flux penetration in nanoscale wedge-shaped superconducting thin films
- Dendritic flux avalanches in superconducting films of different thickness