Magnetic Properties and Recording Characteristics of CoPtB-O Perpendicular Recording Media

CoPtB-O films show a large perpendicular magnetic anisotropy and coercivity with a high saturation magnetization. For these reasons, they are promising high-density, high-output media. The recording characteristics of CoPtB-O perpendicular recording media were investigated. CoPtB-O films were prepared by rf sputtering on glass substrate for use as hard disk media, and their recording characteristics were measured using a MIG type ring head for VCRs with a spring suspension. A large reproduced output was obtained at 7.87 Mfc/m (200 kFCI) using a head with an appropriate gap length of 0.35 m. To obtain a large reproduced output at a high recording density, a medium must be used with a high perpendicular coercivity and a large perpendicular anisotropy, and a head gap length must be chosen which is appropriate to the recording wavelength.