| 摘要 |
PROBLEM TO BE SOLVED: To stabilize an overwriting action by forming an initialization layer of an amorphous alloy of a transition metal and rare earth metal subjected to compsn. modulation in a film thickness direction and making the modulation period of the compsn. modulation smaller on the side of a recording assistance layer. SOLUTION: The recording medium is formed by successively laminating a protective layer 2, an M layer 3 for binary information recording and reproducing, a W layer 4 for recording assistance having the Curie temp. higher than the Curie temp. of this M layer, an S layer 5 for controlling the exchange bonding of the magnetic layer, an I layer 6 for initializing the magnetization direction of the S layer 5 and the W layer 4 and a protective layer 7. The initialization I layer 6 is formed of the amorphous alloy of the transition metal and rare earth metal subjected to the compsn. modulation in the film thickness direction, by which the first I layer 6a and second I layer 6b on the S layer 5 side are formed. The modulation periodλof 6a is made smaller than the modulation periodλ2 of 6b, by which the exchange bonding force within the plane at the boundary with the S layer 5 is made uniform. Since the modulation synchronizationλ2 is long on the protective layer 7 side on the opposite side thereof, the sufficiently large coercive force is obtd. as the whole of the I layer 6.
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