Synthetic ferrimagnetic media

The thermal stability and read-write performance of longitudinal magnetic recording media with antiferromagnetically coupled layers are 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 approximately 45% of the anisotropy energy of the stabilizing layer. 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 a thickness proportional to the magnetization difference between the layers. With these “synthetic ferrimagnetic” structures, thermally stable, low M_rδ and high resolution media are made possible