| 摘要 |
PROBLEM TO BE SOLVED: To suppress the influences of thermal fluctuation by determining the magnetic anisotropic magnetic field and coercive force of a magnetic layer and the magnetic anisotropy const. of a magnetic recording medium to satisfy a specified relation. SOLUTION: The relation between the magnetic anisotropic magnetic field Hk and coercive force Hc of the magnetic layer of a magnetic recording medium are determined to less than Hc/Hk<=0.2. The magnetic anisotropic const. Ku is made to Ku>=2×10<5> J/m<3> . As for the magnetic recording layer having the characteristics, CoPt or a material prepared by adding N or B or a compd. of N and B to four kinds of alloys of CoSm, CoY, CoCe, COPr is used. In this structure, the coercive force also increases and therefore, a bicrystal structure is used to decrease the coercive force. Thus, the gaps are produced among particles in a Cr base layer and the distance among the crystal grain groups of grains having a bicrystal structure can be increased.
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