Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 58: SC: Vortex Dynamics, Vortex Phases, Pinning

TT 58.5: Vortrag

Donnerstag, 17. März 2011, 18:30–18:45, HSZ 301

Formation and propagation of flux avalanches in MgB₂ films — •Sebastian Treiber¹, Claudia Stahl¹, and Joachim Albrecht² — ¹Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart, Germany — ²Hochschule Aalen, Beethovenstrasse 1, 73430 Aalen, Germany

Devices made of MgB₂ are substantially limited by the presence of magnetic flux avalanches at temperatures below 10 K. In this case, quickly moving magnetic vortices create large amounts of heat and magnetic noise.

We found out, that it is necessary to distinguish between mechanisms which are responsible for the formation and the propagation of these avalanches [1]. In addition to the existing knowledge, described in Ref. [2], avalanches form preferably in granular areas with lower current density. This makes a nonlocal description for avalanche-formation necessary. Mechanisms for avalanche-propagation are still under discussion. Since propagation depends on many factors, one has to consider thermal, electrical and superconducting properties as well as the microstructure of the sample. The diverse consequences on formation and propagation explains the preference of avalanches for inhomogeneous superconductors.
S. Treiber and J. Albrecht, New J. Phys. 12, 093043 (2010)
J. Albrecht et al., Phys. Rev. Lett. 98, 117001 (2007)