NANOCRYSTALLINE MATERIALS FOR VIDEO RECORDER HEADS

In present video recorders the magnetic material of the record/playback head is usually a crystalline ferrite. These materials are, however, not so suitable, when substantially finer details on the magnetic tape are required, e.g. for high-definition television (HDTV) recording. The search for an alternative has resulted in a new type of magnetic material: multilayers in which crystalline iron layers of about 10 nm thickness are alternated with even thinner amorphous iron-alloy layers. These 'nanocrystalline' materials combine a high saturation magnetization with a high permeability in the MHz frequency range, allowing video recording at much increased information densities.