Abstract
Acicular barium ferrite particles in which the doping Co2+ ions and Ti4+ ions were substituted for Fe3+ ions have been prepared by the sintering method. The acicular BaCo0.7Ti0.7Fe10.6O19 particles which had coercivity of about 1 kÖe were mixed with a binder, then the resulting mixture was coated on a PET film under a magnetic field of 8 kÖe applied vertically to the surface of the film. The recording characteristics of the acicular barium ferrite magnetic tapes were measured by using commercially available open reel tape deck.
The output waveform of the acicular barium ferrite magnetic tapes showed that the tapes had the perpendicular magnetic anisotropy. However, the low packing density of the particles and the rough surface resulted in the low value of the signal output in the high frequency. Therefore, we attempted to improve the dispersion quality and the spacing loss. The signal output of the improved acicular barium ferrite magnetic tape was about 2 times as large as that of the previously prepared tape.
