1992 年 16 巻 2 号 p. 109-112
CoPtB-O films show a large perpendicular magnetic anisotropy and coercivity with a high saturation magnetization. Therefore, CoPtB-O films are promising for high density and high output media. Recording characteristics of CoPtB-O perpendicular recording media were investigated. CoPtB-O films were prepared by rf sputtering on glass substrates for hard disk, and recording characteristics were measured by using a MIG type ring head for VTR's with a spring suspended mechanism. A large reproduced output was obtained at 7.87 Mfc/m {200 kFCI} using a head with proper gap length of 0.35μm. To obtain a large reproduced output at a high recording density, it is necessary to use medium with a large perpendicular coercivity and a perpendicular anisotropy, and to choose proper head gap length according to the recording wave length.