High-anisotropy nanocomposite films for magnetic recording

This paper presents results on the synthesis and properties of FePt- and CoPt-based high-anisotropy nanocomposite films. These films consist of high anisotropy L1(0) CoPt or FePt particles embedded in a nonmagnetic matrix such as C, SiO2, or B2O3. The grain size and magnetic properties of these films can be controlled by the processing temperatures and the film compositions. Particularly in the FePt:B2O3 films the c-axes of the FePt grains can be made to align along the film normal direction, resulting in films with perpendicular anisotropy. Temperature-dependence of magnetic properties and activation volumes are investigated to understand the magnetization reversal and thermal-activation effects. The potential of these films as high-density recording media is discussed.