heterostructures*

We studied competing magnetic and superconducting interactions in Pr_0.5La_0.2Ca_0.3MnO₃ / YBa₂Cu₃O_7−δ /Pr_0.5La_0.2Ca_0.3MnO₃ (PLCMO/YBCO/PLCMO) heterostructures. A highly sensitive and selective magnetic field-modulated microwave absorption spectroscopy (MFMMS) technique was used to compare the superconducting properties of single YBCO thin films to PLCMO/YBCO/PLCMO heterostructures. The MFMMS showed clear influence of the PLCMO magnetic state on the superconducting transition and vortex dynamics of the YBCO film. Surprisingly, magnetization measurements revealed that the magnetic anisotropy of PLCMO is strongly modified by the superconducting state of the YBCO layer. Our results, in combination with micromagnetic simulations, suggest that the superconductivity changes the temperature-dependent ratio of the ferromagnetic-metallic and antiferromagnetic-insulating domains.  This unusual observation of the effect of superconductivity on magnetism in these well-studied quantum materials when in proximity shows that they are still a rich playground for new physics.