Recording performances of Ba-ferrite coated perpendicular magnetic tapes

Barium-ferrite fine-particle-coated perpendicular magnetic recording tapes have been experimentally fabricated. Typical tapes have Ms= 120 - 130 emu/cc, Hc= 600 - 1500 Oe and perpendicular squareness ratio larger than 0.9. Tape recording performances were measured with a perpendicular head as well as With a ring-shaped head. A good short wavelength response, D50= 76k FRPI, which has never been attained by longitudinally oriented particulate tapes, was obtained; The relationship between perpendicular squareness ratio and output was also investigated to show the importance of perpendicular orientation for attaining a higher recording density.