Structure and magnetic properties of exchange-biased polycrystalline Fe/MnPd bilayers

Abstract

We report the fabrication of polycrystalline Fe/MnPd bilayers, which show the exchange-bias effects. We show that the exchange-bias effect, described by unidirectional anisotropy, is also accompanied by induced uniaxial and fourfold in-plane anisotropy contributions in the system. Using the Stoner-Wohlfarth model, all in-plane anisotropy contributions to the total free energy are determined for the polycrystalline samples from the fit of the in-plane angular dependence of ${H}_{\mathrm{eb}}$ and the coercivity ${H}_{c}.$ A mechanism explaining the presence of the induced higher-order anisotropy contributions in an exchange-bias system is proposed.