  Magnetic nano-objects possess great potential for more efficient data
processing, storage and neuromorphic type of applications. Using high
perpendicular magnetic anisotropy synthetic antiferromagnets in the form of
multilayer-based metamaterials we purposely reduce the antiferromagnetic (AF)
interlayer exchange energy below the out-of-plane demagnetization energy, which
controls the magnetic domain formation. As we show via macroscopic magnetometry
as well as microscopic Lorentz transmission electron microscopy, in this
unusual magnetic energy regime, it becomes possible to stabilize nanometer
scale stripe and bubble textures consisting of ferromagnetic (FM) out-of-plane
domain cores separated by AF in-plane Bloch-type domain walls. This unique
coexistence of mixed FM/AF order on the nanometer scale opens so far unexplored
perspectives in the architecture of magnetic domain landscapes as well as the
design and functionality of individual magnetic textures, such as bubble
domains with alternating chirality.
