Modification of domain-wall propagation in Co nanowires via Ga + irradiation

The propagation of domain walls in polycrystalline Co nanowires grown by focused-electron-beam-induced deposition is explored. We have found that Ga + irradiation via focused ion beam is a suitable method to modify the propagation field of domain walls in magnetic conduits. Magneto-optical Kerr effect measurements show that global Ga + irradiation of the nanowires increases the domain-wall propagation field. Additionally, we have observed by means of scanning transmission X-ray microscopy that it is possible to produce substantial domain-wall pinning via local Ga + irradiation of a narrow region of the nanowire. In both cases, Ga + doses of the order of 10 16 ions/cm 2 are required to produce such effects. These results pave the way for the controlled manipulation of domain walls in Co nanowires via Ga + irradiation. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2013