Imaging the antiparallel magnetic alignment of adjacent Fe and MnAs thin   films
  The magnetic coupling between iron and alpha - MnAs in the epitaxial system Fe/MnAs/GaAs(001) has been studied at the sub-micron scale, using element selective x-ray photoemission electron microscopy. At room temperature, MnAs layers display ridges and grooves, alternating alpha (magnetic) and beta (non-magnetic) phases. The self-organised microstructure of MnAs and the stray fields that it generates govern the local alignment between the Fe and alpha - MnAs magnetization directions, which is mostly antiparallel with a marked dependence upon the magnetic domain size. 
R. Breitwieser, M. Marangolo, J. Luning, N. Jaouen, L. Joly, M.   Eddrief, V. H. Etgens and M. Sacchi