Engineering of exchange bias field and magnetization relaxation with nonmagnetic dilution: The role of the misalignment between anisotropy axes

Abstract In this work, using magnetron sputtering technique we prepare and characterize a series of exchange-biased (Fe70Co30/Ir25Mn75)3 multilayers with antiferromagnetic layer (Ir25Mn75) doped by nonmagnetic MgO to study the misaligned effect of anisotropies on the static exchange bias field (Heb) and the dynamic magnetization relaxation behavior. We demonstrate a strong correlation between the misalignment angle and Heb, as well as the dynamic damping along the easy axis of the Heb, and attributed this to the noncollinear spin structure in ferromagnetic layer. While a different relaxation behavior was observed for the hard axis due to the unidirectional relaxation mechanism in the exchange biased system. Our result may shed new insight in the field of exchange bias, promoting its application in low consumption spintronics devices.