  Heterostructures consisting of a cuprate superconductor YBa2Cu3O7x and a
ruthenate/manganite (SrRuO3/La0.7Sr0.3MnO3) spin valve have been studied by
SQUID magnetometry, ferromagnetic resonances and neutron reflectometry. It was
shown that due to the influence of magnetic proximity effect a magnetic moment
is induced in the superconducting part of heterostructure and at the same time
the magnetic moment is suppressed in the ferromagnetic spin valve. The
experimental value of magnetization induced in the superconductor has the same
order of magnitude with the calculations based on the induced magnetic moment
of Cu atoms due to orbital reconstruction at the superconductor-ferromagnetic
interface. It corresponds also to the model that takes into account the change
in the density of states at a distance of order of the coherence length in the
superconductor. The experimentally obtained characteristic length of
penetration of the magnetic moment into superconductor exceeds the coherence
length for cuprate superconductor. This fact points on the dominance of the
mechanism of the induced magnetic moment of Cu atoms due to orbital
reconstruction.
