  Strong correlated manganites are still under intense research owing to their
complex phase diagrams in terms of the Sr-doping and their sensitivity to
intrinsic and extrinsic structural deformations. Here, we performed x-ray
absorption spectroscopy measurements of manganites bilayers to explore the
effects that a local Sr-doping gradient produce on the charge and
antiferromagnetic anisotropies. In order to gradually tune the Sr-doping level
along the axis perpendicular to the samples we have grown a series of bilayers
with different thicknesses of low-doped manganites (from 0 nm to 6 nm)
deposited over a La0.7Sr0.3MnO3 metallic layer. This strategy permitted us to
resolve with high accuracy the thickness region where the charge and spin
anisotropies vary and the critical thickness tc over which the out of plane
orbital asymmetry does not have any further modifications. We found that the
antiferromagnetic spin axis points preferentially out of the sample plane
regardless the capping layer thickness. However, it tilts partially into the
sample plane far from this critical thickness, owing to the jointed
contributions of the external structural strain and electron doping.
Furthermore, we found that the doping level of the capping layer sensibly
affects the critical thickness, giving clear evidence of the influence exerted
by the electron doping on the orbital and magnetic configurations. These
anisotropy changes induce subtle modifications on the domain reorientation of
the La0.7Sr0.3MnO3, as evidenced from the magnetic hysteresis cycles.
