Oxide manganite/cuprate superlattices are an attractive model system to study the proximity effect in oxide ferromagnet/cuprate superlattices. This report describes recent experimental results obtained on manganite/cuprate heterostructures. The experimental results are discussed in terms of the impact of hole charge transfer from cuprate to manganite layers on the proximity between the oxide ferromagnet and oxide superconductor layers.

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Magneto-optical analysis was performed on YBa2Cu3O7−δ/La1−xSrxMnO3 bilayers grown on twinned LaAlO3 substrates. The twin boundaries in the LaAlO3 substrate induced splitting of the manganite magnetic domains with either in-plane or out-of-plane magnetization, depending on the strontium doping level affecting the magnetic pattern. In the YBa2Cu3O7−δ film, the spontaneous vortex phase, as induced by the out-of-plane magnetic moments in the manganite films, was directly visualized. For vortices nucleated by an external magnetic field, we distinguished different vortex dynamics due to the out-of-plane magnetic moments located either in correlated defects (twin boundaries) or in a homogeneous part of the heterostructure. Vortex guidance over the magnetic domains, dependent only on the relative orientation of the vortex driving force with respect to the local out-of-plane magnetization in the manganite layer, was observed. By means of the inversion of the Biot–Savart law, the local modulations of the supercurrent by the spontaneous vortex phase were imaged. Moreover, a local enhanced/depressed critical current was found across domains of opposite magnetic polarization.