Europhys. Lett.
Volume 63, Number 6, September 2003
Page(s) 881 - 887
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00603-9
Europhys. Lett., 63 (6) , pp. 881-887 (2003)

Hysteretic behavior of critical currents in heterostructures of high-temperature superconductors and ferromagnets

J. Albrecht, S. Soltan and H.-U. Habermeier

Max-Planck-Institut für Festkörperforschung - Heisenbergstr. 1 D-70569 Stuttgart, Germany

(Received 8 May 2003; accepted in final form 7 July 2003)

We have grown bilayer structures of the ferromagnet $\chem{SrRuO_3}$ and the high-temperature superconductor $\chem{YBa_2Cu_3O_{7-\delta}}$ on single crystalline $\chem{LaSrGaO_4}$ substrates by pulsed laser deposition. By means of quantitative magneto-optics, the critical current density in the superconducting film is measured and it is found that it strongly depends on the magnetization state of the ferromagnetic layer. The critical current density shows a hysteretic behavior that is strongly related to the magnetic hysteresis loop of the ferromagnet.

74.78.Fk - Multilayers, superlattices, heterostructures.
74.25.Qt - Vortex lattices, flux pinning, flux creep.
74.72.Bk - $\chem{Y}$-based cuprates.

© EDP Sciences 2003