Properties, preparation, advances and limitations of materials and media for perpendicular recording

The trends in perpendicular magnetic recording research are discussed, with emphasis on clarifying the trend of research on recording media, their materials, and head materials. Among numerous proposed perpendicular recording media materials, barium ferrite powder and evaporated Co-Cr films seem to lead in practical applications, since their mass production seems to be very successful. There still exist crucial points in their development. However, improvements are continuously taking place. Other candidate perpendicular recording media for a device which has a ring head are also discussed. It is concluded that, for future high-density magnetic recording, utilizing fully the perpendicular component of media magnetization will furnish the key to success