Relation between exchange anisotropy and magnetization reversal asymmetry in Fe/MnF2 bilayers

The angular dependence of the magnetic anisotropy of exchange biased Fe/MnF2 bilayers was measured. Below the Neel temperature of the antiferromagnetic MnF2 layer, an exchange anisotropy is observed which consists of unidirectional, uniaxial, threefold and fourfold symmetry components. The threefold exchange anisotropy term is responsible for the asymmetric magnetization reversal process recently observed in this system.