Magnetic domains and magnetization reversal of ion-induced magnetically patterned RKKY-coupled Ni81Fe19/Ru/Co90Fe10 films

Pure magnetic patterning by means of ion beam irradiation of magnetic thin films and multilayers result often from a post deposition local modification of the interface structure with only minor effects on the film topography. In the study presented here a 60 keV fine focused Co ion beam was used to change the coupling in a Ni81Fe19/Ru/Co90Fe10 structure from antiferromagnetic to ferromagnetic on a micron scale. Thereby an artificial structure with locally varying interlayer exchange coupling and therefore magnetization alignment is produced. High-resolution fullfield x-ray microscopy is used to determine the magnetic domain configuration during the magnetization reversal process locally and layer resolved dueto the element specific contrast in circular x-ray dichroism. In the magnetically patterned structure there is in addition to the locally varying interlayer exchange coupling across the Ru layer also the direct exchange coupling within each ferromagnetic layer present. Therefore the magnetization reversal behaviour of the irradiated stripes is largely influenced by the surrounding magnetic film.