  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.
