Manipulation of AF-Coupled Thin Film Systems by Ion Beam Irradiation

The tuning of the magnetic properties of antiferromagnetically (AF) coupled multilayer films by ion beam irradiation has been investigated. Stacks of Co/Pd respectively Co/Pt multilayers, AF-coupled by Ru or Ir interlayers, have been useful for studying the energy contribution of interlayer exchange, perpendicular anisotropy and long range dipole interactions. The system shows a complex mixture of magnetic phases that can be tuned by the number of repeats of the multilayers (X). A lateral homogeneous AF remanent structure occurs for small X due to the dominance of the AF-coupling. For large X the demagnetisation energy prevails and ferromagnetic stripe domains evolve. With ion irradiation the balance of the energy contributions can be locally manipulated, thus a lateral heterogeneous structure of magnetic phases may be realised. Initial irradiation studies will be discussed.