A study on the macroscopic properties of hard/soft bilayers

The dependence of the macroscopic properties of the soft layer on the hard-layer magnetization and microstructure in exchange spring bilayers is studied. The exchange bias field experienced by the soft layer varies proportionally with magnetization as well as magnetic hardness of the hard layer. On the other hand, there is an inverse relationship between the coercivity of the soft layer and the hard layer magnetization, as well as between the coercivities of the two layers. Domain wall and interface processes offer a qualitative explanation of the results. A vector Preisach-type model for exchange spring bilayers is used to investigate the above.