Magneto-optical analysis of the local magnetic field distribution across superconducting/magnetic bilayers

The paper reports on an investigation of the superconducting and magnetic properties of a YBa2Cu3O7/La0.67Sr0.33MnO3 bilayer grown on LaAlO3. Beside structural, transport and optical characterisation the magneto-optical analysis was the main tool to study the local properties of the bilayer. The optical analysis shows the twinned structure exhibited by the substrate and the magneto-optical analysis allows visualizing the manganite magnetic domain structure with in plane-field magnetization, divided by domain walls where magnetic moments tilt out of the film plane. After cooling below Tc the domain-wall stray field induces vortex decoration patterns. Under an external magnetic field flux penetration is strongly modulated by the manganite domain walls. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)