2005/05/06 by D. V. Shantsev, A. V. Bobyl, Y. M. Galperin +2
Engineering · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.72.024541
published as Phys. Rev. B 72, 024541 (2005) · 8 pages, 10 figures, submitted to PRB
arxiv created 2005/05/06 · openalex publication_date 2005/07/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Magneto-optical imaging is used to visualize vortex avalanches in MgB2 films at 4\phantom\rule0.3em0exK. Avalanches ranging from 50 to 50 000 vortices were detected. The size distribution function has a clear peak whose position moves towards larger sizes as the applied field increases. This field dependence as well as variation of flux density profile during an avalanche is well described by a proposed model assuming a thermal origin of the avalanches. The model is based on the adiabatic approach and takes into account nonlocal electrodynamics in thin superconductors. The threshold field for thermal avalanches is predicted to be much smaller than that for thick superconductors, in agreement with the experiment.