Angular dependence of exchange coupling in ferromagnet/antiferromagnet bilayers

Abstract

Angular dependence of the exchange coupling in a NiFe/CoO bilayer film has been measured. Different angular dependence and symmetry have been observed for the exchange field ${H}_{E}$ and the coercivity ${H}_{C}.$ The values of ${H}_{E}$ and ${H}_{C}$ are due to unidirectional and uniaxial components of the magnetic anisotropy energy, in which the odd and the even terms lead to ${H}_{E}$ and ${H}_{C},$ respectively. The proposed free energy accounts for the experimental results.