Abstract
Thin superlattices with 1:2 ratio of bulk antiferromagnetics SrMnO3 :RMnO3 (R=Lantanide) are
known to exhibit ferrmagnetism due to electronic reconstruction. In this study the limited range of
the charge transfer is used to generate thin ferromagnetic layers adjacent to A-type antiferromag-
netic order in superlattices with thicker RMnO3 layers. The ferromagnetic layers strongly couple to
the antiferromagnetic spins, which mediates coupling between neighboring antiferromagnets. Using
a novel interference based neutron diffraction technique, we directly observed the relative orienta-
tion of the antiferromagnetic layers and confirm the magnetic structure induced by this coupling
using NdMnO3/SrMnO3 superlattices. Ferromagnetism in the thin interlayer regions was probed
by polarized neutron reflectometry. Density functional theory calculations were applied to analyze
the driving forces for the exchange in more detail. The calculations reveal a ferromagnetic coupling
and charge transfer across the interface. These results constitute promising steps on a path towards
magnetic control of antiferromagnetic arrangements as would be necessary in spin-based multiferroic
devices with strong magnetoelectric coupling.
