For a model system consisting of a ferromagnetic layer exchange coupled to an antiferromagnetic layer with a compensated interface, detailed mean-field-type calculations are performed. Both the coercive field and the exchange bias field are calculated. For the coercive field, a rather broad enhancement around the Néel temperature $T_N$ of the antiferromagnetic layer is found irrespective of whether the antiferromagnetic layer is structurally disordered or not, while exchange bias is only found for disordered systems. We show that the observed enhancement of the coercivity around $T_N$ also found experimentally and the occurrence of exchange bias are of different origin.

• Received 19 October 2004

DOI:https://doi.org/10.1103/PhysRevB.71.064413