The application of barium ferrite particles in advanced recording media

Barium ferrite is a leading candidate material for advanced magnetic recording media. Tapes and disks made with it offer output amplitudes at recording densities of current interest (75-100 kfci) that far exceed those of advanced acicular oxides and are comparable to those of many commercially available media made with metallic particles (MP). The very high coercivity values available with barium ferrite make it an attractive material for future applications with recording densities well above 100 kcfi. These applications will employ high-induction writing head materials to take advantage of the high media coercivity. They will also use high-sensitivity (MR or GMR) reading heads, so that the relatively low moment of barium ferrite will not be a disadvantage and may in fact be desirable for minimizing transition broadening. Although the output amplitudes offered by advanced barium ferrite media are competitive with those of many MP media, it is with respect to signal-to-noise properties that barium ferrite is most attractive. These properties result from the very small particle sizes that are available.