Perpendicular anisotropy and out-of-plane exchange bias in nanoscale antidot arrays

Abstract

We report on tailoring the perpendicular anisotropy, and out-ofplane exchange bias in (Co/Pd) multilayer exchange coupled to CoO, by patterning them into ordered arrays of antidots or 'holes'. The coercivity in the multilayers is enhanced due to strong domain wall pinning in the vicinity of the antidots. We also observed a smaller degree of asymmetry in the reversal of the exchange-biased antidots as compared to the continuous film. Moreover, a strong interplay between thermal activation and CoO domain size confinement results in the exchange bias for the antidots being either smaller or larger than the continuous film. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.