Evolution of magnetic phases and orbital occupation in (SrMnO3)n/(LaMnO3)2n superlattices

The magnetic and electronic modifications induced at the interfaces in (SrMnO(3))(n)/(LaMnO(3))(2n) superlattices have been investigated by linear and circular magnetic dichroism in the Mn L(2,3) x-ray absorption spectra. Together with theoretical calculations, our data demonstrate that the charge redistribution across interfaces favors in-plane ferromagnetic (FM) order and e(g)(x(2)-y(2)) orbital occupation, in agreement with the average strain. Far from interfaces, inside LaMnO(3), electron localization and local strain favor antiferromagnetism (AFM) and e(g)(3z(2)-r(2)) orbital occupation. For n=1 the high density of interfacial planes ultimately leads to dominant FM order forcing the residual AFM phase to be in-plane too, while for n >= 5 the FM layers are separated by AFM regions having out-of-plane spin orientation.