Memory of frozen and rotatable antiferromagnetic spins

We combined x-ray magnetic linear and circular dichroism together with magnetooptic Kerr effect measurements in order to follow the magnetic properties of epitaxial CoO(111)/Fe(110) and NiO(111)/Fe(110) bilayers. We find that in both studied cases ferromagnetic sublayer plays a dominant role and determines the magnetic state of the neighboring antiferromagnet, however different interaction scenarios are observed. In CoO/Fe bilayers the antiferromagnetic spins are frozen and their orientation is imprinted by magnetization of Fe layer as the system passes the Néel temperature of CoO. For NiO/Fe bilayers, the antiferromagnetic spins are rotatable and always follow the reorientation of Fe magnetization that can be controlled by external magnetic field or via the temperature and thickness driven spin reorientation transition in Fe(110).