Magnetic proximity effect in $\mathbf{YB}{\mathbf{a}}_2\mathbf{C}{\mathbf{u}}_3{\mathbf{O}}_7/L{\mathbf{a}}_{2/3}\mathbf{C}{\mathbf{a}}_{1/3}\mathbf{Mn}{\mathbf{O}}_3$ and $\mathbf{YB}{\mathbf{a}}_2\mathbf{C}{\mathbf{u}}_3{\mathbf{O}}_7/LaMn{\mathbf{O}}_{3+\hat{\mathbf{I}}´}$ superlattices

Abstract

Using neutron reflectometry and resonant x-ray techniques we studied the magnetic proximity effect (MPE) in superlattices composed of superconducting YBa${}_2$Cu${}_3$O${}_7$ (YBCO) and ferromagnetic-metallic (FM-M) La${}_{0.67}$Ca${}_{0.33}$MnO${}_3$ (LCMO) or ferromagnetic-insulating (FM-I) LaMnO${}_{3+\hat{I}´}$ (LMO). We find that the MPE strongly depends on the electronic state of the manganite layers, being pronounced for the FM-M LCMO and almost absent for FM-I LMO. We also detail the change of the magnetic depth profile due to the MPE and provide evidence for its intrinsic nature.

5 pages, 4 figures