Magnetic Proximity Effect in YBa2Cu307/La2/3/Ca1/3Mn03 and YBa2Cu307/LaMn03+&b.delta; Superlattices.

Using neutron reflectometry and resonant x-ray techniques we studied the magnetic proximity effect (MPE) in superlattices composed of superconducting YBa2Cu307 and ferromagnetic-metallic Lao.67Cao.33Mn03 or ferromagnetic-insulating LaMn03+&b.delta;. We find that the MPE strongly depends on the electronic state of the manganite layers, being pronounced for the ferromagnetic-metallic Lao.67Cao.33Mn03 and almost absent for ferromagnetic-insulating LaMn03+&b.delta;. We also detail the change of the magnetic depth profile due to the MPE and provide evidence for its intrinsic nature. [ABSTRACT FROM AUTHOR]