Magnetic Proximity Effect in YBa2Cu3O7/La2/3Ca1/3MnO3 and YBa2Cu3O7/LaMnO3+δ Superlattices

Using neutron reflectometry and resonant x-ray techniques we studied the magnetic proximity effect (MPE) in superlattices composed of superconducting YBa2Cu3O7 and ferromagnetic-metallic La0.67Ca0.33MnO3 or ferromagnetic-insulating LaMnO3+delta. We find that the MPE strongly depends on the electronic state of the manganite layers, being pronounced for the ferromagnetic-metallic La0.67Ca0.33MnO3 and almost absent for ferromagnetic-insulating LaMnO3+delta. We also detail the change of the magnetic depth profile due to the MPE and provide evidence for its intrinsic nature.