Coupling between perpendicular and in-plane magnetic anisotropy layers in amorphous heterostructures.

In magnetic recording media the superparamagnetic effect refers to the spontaneous change in magnetization due to thermal instability,caused by size limitation of the magnetically decoupled grains of the recording material. To combat this effect it has been proposed to use tilted magnetic recording materials, where the top magnetic layer is tilted from the film normal. We propose to use amorphous heterostructures composed of exchange coupled layers with in-plane and perpendicular magnetic anisotropy to achieve tilted magnetic anisotropy. There is great potential for engineering amorphous heterostructures so that they display a specific complex magnetic response. We propose to use polarized neutron reflectivity to determine the magnetic profile of such structures. This will allow the design of heterostructures with predefined magnetization and switching characteristics.