Regensburg 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 64: Superconductivity: Heterostructures, Andreev Scattering, Vortex Physics

TT 64.3: Vortrag

Donnerstag, 14. März 2013, 15:30–15:45, H21

Interaction of ultra soft magnetic materials with the high-T_c superconductor YBCO — •Claudia Stahl¹, Sebastian Treiber¹, Patrick Walker^1,2, Gisela Schütz¹, and Joachim Albrecht² — ¹Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart — ²Aalen University, Beethovenstraße 1, 73430 Aalen

We have grown bilayers of optimally doped YBa₂Cu₃O_7−δ (YBCO) and ferromagnetic CoFeB on single-crystalline substrates by pulsed laser deposition and sputtering. These heterostructures are typically composed of about 100 nm YBCO and several 10 nm of CoFeB. Regarding the superconductor, the properties of the YBCO film change as a consequence of the vicinity of the ferromagnet. In detail we investigated the critical current density as a function of temperature, applied field and time as well as the transition temperature by SQUID magnetization measurements and quantitative magneto-optical measurements. The amorphous material CoFeB exhibits an in plane anisotropy and a very low coercivity. From magneto-optical images we find that the flux line lattice of the superconductor is mapped into the magnet and still visible as significant magnetic out-of-plane contrast at room temperature. We discuss this phenomenon as a new route to high-resolution mapping of the flux line distribution on a nanometer scale.