| 摘要 |
PURPOSE:To compatibly provide both the higher density of recording and the assurance of corrosion resistance by providing an 1st magnetic layer having cobalt in component elements and a 2nd magnetic layer essentially consisting of iron nitride on a nonmagnetic substrate. CONSTITUTION:The 1st magnetic layer 15 having the cobalt in the component elements and the 2nd magnetic layer 16 essentially consisting of the iron nitride are laminated on the nonmagnetic substrate 11. The 1st magnetic layer 15 has the cobalt in the component elements which are exemplified by the element consisting of Co and Ni, the element added with further at least one element selected for Fc, P, W, Pt, and Cr and further the element consisting of Co and at least one element selected from Pt, Y, La, Cc, Pr, Sm, Nd, and Pm. The extremely good corrosion resistance is obtd. with the film which consists of the iron nitride and is used as the 2nd magnetic layer. Said film is superior in durability to the 1st magnetic layer. The film formed with the iron nitride in the crystalline state such as gamma-Fc4N or alpha-Fc3N obtd. by selecting the other film forming conditions such as substrate temp. excels not only in the corrosion resistance but in magnetic characteristics such as satd. magnetization and coercive force as well.
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