Abstract

Magnetic flux penetration and trapped flux patterns formed into a MgB2 film during the increase and the subsequent decrease of the applied external magnetic field were studied using magneto-optical imaging. The film was grown by electron-beam evaporation and exhibits a granular structure. The non-homogeneous fan-like shaped penetration, already pointed out in the literature, was observed. To investigate the origin of this kind of penetration, a quantitative approach was chosen. The induction magnetic field map and the corresponding contour map of a framed zone show many isolated loops originating from the granular nature of the sample. Inside such loops, an estimation of the local current density was made through the inversion of the Biot–Savart law. All the results point towards the conclusions that the fan-like shaped patterns do mirror the percolation of dissipation paths. Along these paths, some interfaces, distributed in a hierarchical order, play the role of either pinning barriers or easy-flow channels.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.