[en] Though Superconductor/Ferromagnet hybrids is a widely studied system, application of hard magnetic materials as sources of vortex pinning remains relatively unexplored. They offer a number of advantages over softer magnetic materials, like greater stability and larger magnetic field amplitudes. Recently, a promising technique, thermomagnetic patterning (TMP), has been developed to prepare micromagnets, which serve as micro flux sources to produce magnetic fields spatially modulated at the micron scale. Permanent magnetic structures prepared using TMP present an interesting and so far unexplored option for controlled artificial pinning.
We have investigated the vortex matter in superconductor/TMP micromagnet heterostructures (Nb-NdFeB) using quantitative Magneto-Optical Imaging (MOI). Comprehensive protocols have been developed for calibrating and converting Faraday rotation data acquired by MOI to magnetic field maps. These protocols reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields associated with the magnetic layer in its vicinity. Further, TMP micromagnet structures have been imprinted in a permalloy (Py) layer following a protocol reported earlier to obtain flexible magnetic landscapes for flux guidance in a Nb layer below it. Both smooth flux penetration and vortex avalanches in Nb are observed to be strongly influenced by the micromagnetic patterns. Our study offers new insights into the peculiarities of the vortex state in these superconductor-micromagnet heterostructures.
Research center :
EPNM - Experimental Physics of Nanostructured Materials
Disciplines :
Physics
Author, co-author :
Shaw, Gorky ; Université de Liège > Département de physique > Physique expérimentale des matériaux nanostructurés
Language :
English
Title :
A novel approach towards manipulation of vortex matter in a superconductor with micromagnetic structures
Publication date :
01 June 2017
Number of pages :
89
Event name :
'The 16th International Workshop on Vortex Matter in Superconductors (VORTEX2017)
Event organizer :
International Institute of Physics, Universidade Federal do Rio Grande do Norte
FP7 - 600405 - BEIPD - Be International Post-Doc - Euregio and Greater Region
Name of the research project :
Vortex matter in heterostructures of superconductors and thermomagnetically patterned micromagnets
Funders :
ULiège - Université de Liège [BE] UE - Union Européenne [BE] CE - Commission Européenne [BE]
Commentary :
All presentations in the conference, including mine, were broadcast live on YouTube.
My presentation can be watched on YouTube at https://youtu.be/U6agSvgfDuY.