MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To make reducible the influence of a heat fluctuation and to increase the recording density by consisting a magnetic recording layer of an amorphous PrTbFeCo alloy having perpendicular magnetic anisotropy. SOLUTION: A PRTbFeCo alloy film as a magnetic recording layer 2 is formed on a glass substrate 1 and a Ta film of an oxidation preventing layer 3 is formed thereon. A complex target having Pr, Tb and Co pellets disposed on a Fe target is used for formation of the PrTbFeCo alloy film to be the magnetic recording layer 2. A squareness ratio of residual magnetization to saturation magnetization is nearly equal to 1 and a great reproducing output can be obtained even at the time of a high density recording. The attenuation with time of recorded magnetization is reduced and the record is stably preserved for a long time because there is only little influence of heat fluctuation. 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.