Parts | Days | Selection | Search | Downloads | Help
TT: Tiefe Temperaturen
TT 7: Superconductivity & Solids At Low Temperature - Poster Session
TT 7.60: Poster
Monday, March 27, 2006, 14:00–17:45, P1
Enhancement of the vortex pinning in superconducting MgB2 films — •Anatolie Sidorenko1,2,3, Vladimir Zdravkov1,2, Christian Leierer2, Andreas Heinrich2, Siegfried Horn2, Reinhard Tidecks2, Achim Wixforth2, Thomas Koch3,4, and Thomas Schimmel3,4 — 1IAP, LISES, ASM, Kishinev, Moldova — 2IP, Universität Augsburg, Germany — 3AP, Universität Karlsruhe, Germany — 4INT, Forschungszentrum Karlsruhe, Germany
Superconducting MgB2 films have extremely high critical current density, up to jc ∼ 107/cm2 at 15 K in zero magnetic field what makes this novel superconductor very attractive for technical applications. But magnesium diboride exhibits a rapid loss of the current carrying capabilities in strong magnetic fields, caused by thermomagnetic instabilities leading to a rapid decrease of the activation energy for magnetic flux motion for U0(B) in fields of B > 1 Tesla. There are two possible ways to solve the problem of the too low pinning force for high magnetic fields: a) by covering the MgB2 film with an electronicly isolated highly thermoconducting metallic layer to prevent thermomagnetic instabilities; b) by embedding artificial pinning centers within the film to increase the pinning force and thus the activation barrier for thermally activated flux flow. In the present work we report about the results of our experiments where we used both ways: a) coating of the MgB2 film with Cu-layers (0.3 µ m − 1.0 µ m thick) for thermo stabilization; b) the adsorption of ferromagnet nanoparticles (10nm - 50nm Fe and Ni particles) on the surface of the MgB2 film.