| 摘要 |
PROBLEM TO BE SOLVED: To obtain both of S/N and thermal stability and to obtain high density by forming an intraplane magnetization recording layer as a multilayer and forming a controlling layer for exchange coupling force between the recording layers. SOLUTION: This magnetic disk recording medium includes an Al or glass substrate 1, a base layer 2 such as Cr and a diamond like carbon surface protective film 5, and the medium has two layers of intraplane magnetization recording layers 3, 5 and a controlling layer 4 for exchange coupling force between these layers. The intraplane magnetization recording layers 3, 5 are formed from CoCr in high vacuum of a DC magnetron sputtering device, and the controlling layer 4 for exchange coupling force is formed from an alloy of Co and nonmagnetic elements, such as CoCr, CoNiCr, CoNiAl and CoSi. The compsn. ratio of Co in the controlling layer 4 for exchange coupling force is specified to 40 to 70%, and its film thickness preferably ranges from 0.5 to 10 nm. Thus, the product of the saturation magnetization and the coercive force of the controlling layer 4 for exchange coupling force is specified to be equal to or smaller than the product of the saturation magnetization and the coercive force of the intraplane magnetization recording layers 3, 5.
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