Dynamic Properties of Perpendicular Magnetic Recording Tape Coated with Acicular Ba-Ferrite Media

Magnetic properties of a particulate film fabricated from acicular Ba-ferrite microparticles, coated onto a plastic tape, were evaluated. Squareness ratio measurements showed that this fine dispersion of particles in paint 1) was clearly oriented in the direction of their easy magnetization axis after orientation in a magnetic field, 2) is much more readily formed into a coating film than hexagonal-plate-form Ba-ferrite particles, and 3) has a smooth magnetic field orientation. The hysteresis measurements showed that acicular Ba-ferrite particles have an excellent perpendicular magnetic anisotropy.