Nanocrystalline Materials for video recorder heads

In present video recorders the magnetic materials 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.