Unveiling the Mechanisms Governing the Exchange Coupling and Coercivity Modifications in Annealed or Ion-Irradiated Ir−Mn/Fe/Co and Ir−Mn/Ni−Fe/Co films

Manipulating the exchange coupling at magnetic interfaces is crucial to spintronic devices. This study shows that inserting a very thin ferromagnetic spacer at the interface of a ferromagnet/antiferromagnet Co/Ir-Mn film substantially strengthens the coupling (if there are no important interfacial defects or interdiffusion in the antiferromagnet). Furthermore, although a Fe spacer film presents the same exchange bias after annealing or He-ion irradiation, its coercivity increases threefold after irradiation. This provides a way to fine-tune the characteristics of such structures.