Synthetic ferrimagnetic media

The thermal stability and read-write performance of longitudinal magnetic recording media with antiferromagnetically coupled layers were investigated. The thermal stability is strongly dependent on the interaction between layers and the anisotropy energy of the stabilizing layer or layers. For media with two coupled layers, the energy barrier is increased by 30% to 80% of the anisotropy energy of the stabilizing layer, depending on the strength of the interaction. Although the total thickness is larger compared to a conventional medium with the same remanence magnetization and thickness product Mrδ, the resolution is higher and depends on the difference in thickness between the layers. With these synthetic ferrimagnetic structures, thermally stable, low Mrδ and high-resolution media are made possible with an areal density advantage of at least 1.75 times that of conventional longitudinal recording media.