Tuning exchange bias in Ni/FeF_2 heterostructures using antidot arrays

摘要

The transition from positive to negative exchange bias can be systematically tuned with antidot arrays artificially introduced into Ni/FeF_2 ferromagnetic/antiferromagnetic heterostructures. These results are a consequence of the energy balance and suggest that the nanostructure plays a key role in the formation of pinned uncompensated spin regions in the antiferromagnetic FeF_2 layer. These noninterfacial magnetic moments created at the antidot faces favor the onset of positive exchange bias at lower cooling fields.