Magnetic Recording Properties of Double Layered Coating Media

Double-layered particulate media were prepared with excellent magnetic recording characteristics over a wide frequency range. Video luminance signals were recorded only to a depth of 0.3 ¿m from the tape surface; however, video chrominance signals were recorded to a depth of 0.6 ¿m from the surface. By utilizing these characteristics, high-coercivity magnetic particles suitable for recording high-frequency signals can be used in the upper layer of the medium. However, performance is affected by the thickness of the upper layer and the coercive force of each layer. Hence these parameters should be chosen carefully, taking into account the recording depths of different signals.