IrMn as exchange-biasing material in systems with perpendicular magnetic anisotropy

Abstract

Contact between a Co/Pt multilayer and an IrMn film leads to perpendicular exchange bias. The exchange bias field does not depend on the degree of (111) film texture and for Co/Pt multilayers with IrMn at the bottom it can be enhanced by magnetic field annealing. The perpendicular exchange bias of the Co/Pt–IrMn system is limited by a misalignment between the Co spins and the film normal, which is due to a negative magnetic anisotropy contribution from the Co/IrMn interface (KSCo/IrMn = −0.09 mJ/m2). The insertion of a 3 Å thick Pt layer at the Co/IrMn interface maximizes the perpendicular exchange-bias field.