Magnetic domain pinning in an anisotropy-engineered GdTbFe thin film

Focused ion beam irradiation was used to reduce locally the perpendicular anisotropy of magnetic thin films in rectangular lattices of 50nm sized dots. The effect of the anisotropy patterns, differing in ion fluence and interdot spacing, on the magnetization reversal process was determined in q space with x-ray resonant magnetic scattering and in real space with magnetic force microscopy. At remanence only a slight alignment of the irregularly shaped domains is observed. In perpendicular magnetic fields, however, the high field bubble domains display a pronounced localization on the dots, showing that this form of local anisotropy reduction is a highly efficient way of domain positioning.