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TT: Fachverband Tiefe Temperaturen
TT 34: Superconductivity: Heterostructures
TT 34.6: Talk
Tuesday, April 1, 2014, 12:45–13:00, HSZ 201
Measuring local magnetic fields in superconductors via XMCD — •Claudia Stahl1, Stephen Ruoß1,2, Patrick Audehm1, Markus Weigand1, Gisela Schütz1, and Joachim Albrecht2 — 1Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany — 2Aalen University, Beethovenstraße 1, 73430 Aalen
We use soft ferromagnetic thin films in order to map the magnetic flux line distribution in superconductors. For that purpose amorphous CoFeB is directly deposited on top of high-Tc superconducting YBCO structures. The magnetic stray fields of supercurrents lead to a local reorientation of the magnetic moments in the ferromagnet.
Using polarized x-rays it is possible to measure the local magnetization via the XMCD effect. With XMCD spectroscopy we find a temperature-dependent signal in the CoFeB layer which can be attributed to the currents flowing in the superconductor. This signal can be additionally measured with high spatial resolution paving the way to x-ray microscopy of magnetic structures in superconductors. The measurements are carried out at our scanning x-ray microscope MAXYMUS and our own dedicated reflectometry endstation at Bessy II of the HZB in Berlin.