Lock in of magnetic stripe domains to pinning lattices produced by focused ion-beam patterning

With focused ion-beam irradiation it is possible to engineer the anisotropy of magnetic films on nanometer length scales. We used this technique to write square lattices of artificial domain-wall pinning centers in a perpendicular anisotropy GdFe film displaying a well-defined stripe domain pattern. We observe a clear lock in of the intrinsic meandering stripe pattern to the pinning lattices, resulting in highly ordered domain patterns. We find that at remanence the dots pin the domain walls, while in perpendicular applied magnetic fields they host the down domains.