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

We report the fabrication of polycrystalline Fe/MnPd bilayers, which show t he exchange-bias effects. We show that the exchange-bias effect, described by unidirectional anisotropy, is also accompanied by induced uniaxial and f ourfold in-plane anisotropy contributions in the system. Using the Stoner-W ohlfarth model, all in-plane anisotropy contributions to the total free ene rgy are determined for the polycrystalline samples from the fit of the in-p lane angular dependence of H-eb and the coercivity H-c. A mechanism explain ing the presence of the induced higher-order anisotropy contributions in an exchange-bias system is proposed.