Temperature dependence of the exchange-bias field of ferromagnetic layers coupled with antiferromagnetic layers

The temperature dependence of the exchange-bias field of a ferromagnetic layer coupled with an antiferromagnetic layer is studied. The focus is on the phenomenon that the exchange-bias field of some ferromagnet-antiferromagnet (F-AF) coupled systems does not show a monotonic dependence on temperature. Instead, the exchange-bias field peaks at some temperature for some ferromagnet-antiferromagnet coupled systems. This phenomenon is successfully explained by a model proposed recently. It is predicted that it is more likely to observe a peak of the exchange bias field of a F-AF system versus temperature if the N\'eel temperature is higher than the Curie temperature and/or the AF layer is relatively thin. This prediction has been well supported by experimental data.