Micromagnetic calculations of bias field and coercivity of compensated ferromagnetic antiferromagnetic bilayers

Abstract

Exchange bias in polycrystalline IrMn/NiFe was found at perfectly compensated interfaces. The energy associated with unidirectional anisotropy is stored in lateral domain walls in the antiferromagnet. In addition to exchange bias, this mechanism leads to a training effect. The bias field shows a maximum of μ0Hb=4 mT at an antiferromagnetic layer thickness of 22 nm. The coercivities are on the order of μ0Hc=10 mT. The coercive field increases with decreasing intergrain exchange interactions within the ferromagnet.