Magnetic Proximity Effect inYBa2Cu3O7/La2/3Ca1/

Abstract

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 LaMnO(3+δ). 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 LaMnO(3+δ). We also detail the change of the magnetic depth profile due to the MPE and provide evidence for its intrinsic nature.

Depth profile of the ferromagnetic order in a YBa2Cu3O7/LaUribe-Laverde1, Satapathy2, Marozau3 et al. 2013Phys. Rev. BSelf Cite

“…31, this decrease is even anomalously enhanced below the superconducting transition temperature. Additional evidence for an intrinsic electronic origin of the depleted layers in the YBCO/LCMO SL comes from the observation that the magnetic proximity effect and thus these depleted layers are absent for a corresponding YBCO/LaMnO 3+δ SL for which the manganite layers are insulating 31 . The large FM moments of the Mn ions persist here right up to the interface.…”

“…Hoffmann et al reported an enhancement in the Mn 3d occupation next to the interface and concluded that their PNR data support the dead layer model 27 . On the other hand, Chakhalian et al reported x-ray magnetic circular dichroism (XMCD) data which established the presence of a ferromagnetic Cu moment and thus were interpreted in terms of the "inverse proximity effect model" 28 31 . On this SL they performed a combination of PNR, XMCD and x-ray resonant magnetic reflectometry (XRMR) which showed that the magnetic proximity effect at the YBCO/LCMO interface involves in fact both effects, i.e.…”

On the explanation of the paramagnetic Meissner effect in superconductor/ferromagnet heterostructures

“…Later, however, PME was observed in conventional superconductors, like Al or Nb, which required a less exotic explanation (see review [1] on the PME in bulk superconductors). One of such explanations is based on flux trapping below T C with further compression upon cooling [2,3].A similar effect, the increase of magnetic moment, was also observed recently in superconductor/ ferromagnet heterostructures (S/F) of different compositions [4][5][6][7][8][9][10] with both HTSC and conventional superconductors. For the explanation of the PME in S/F structures different models based on electrodynamical or exchange coupling mechanisms were proposed.…”

Interfacial effects revealed by ultrafast relaxation dynamics inBiFeO3/YBa2Cu3O7bilayers

“…Various x-ray and neutron techniques have been used to study bilayer/trilayer/superlattice HTSC-manganite heterostructures, such as YBCO/LCMO (La 1−x Ca x MnO 3 ) and YBCO/LSMO. [15][16][17][18][19] These studies reveal (a) a strongly (but not totally) suppressed Mn ferromagnetic moment at the manganite side of the interface, and/or (b) a small ferromagnetic Cu moment developing on the HTSC side of the interface. This is consistent with the observation of a reduced saturation magnetization per manganite layer compared to the bulk value.…”