MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To reduce the influence of thermal disturbance and to increase the recording density by incorporating an amorphous PrTbFe alloy having a perpendicular magnetic anisotropy in a magnetic recording layer. SOLUTION: The PrTbFe alloy film is formed as the magnetic recording layer 2 on a glass substrate 1 and a Ta film of an oxidation preventing layer 3 is formed thereon. A complex target having Pr and Tb pellets disposed on a Fe target is used for formation of the PrTbFe alloy film to be the magnetic recording layer 2. Any of the films is formed by utilizing a DC magnetron sputtering method under a prescribed film-forming condition. The squareness ratio of residual magnetization to saturation magnetization is nearly equal to 1 and great reproducing output can be obtained as residual magnetization is large even at the time of a high density recording. The temporal attenuation of recorded magnetization is small and the record is stably preserved for a long time because there is only little influence of thermal disturbance. And, there is no crystal grain in a magnetization transition area and no disturbance of magnetization due to exchange interaction among the crystal grains and therefore the noise of the medium can be reduced because the film is amorphous.