| 摘要 |
PURPOSE:To permit over writing like with a magnetic recording medium by providing perpendicularly magnetized films having specific three-layered structure on a substrate and forming the same so as to satisfy prescribed conditions. CONSTITUTION:This medium has at least the perpendicularly magnetized films having the three-layered structure consisting of a 1st magnetic layer 1 having a Curie point T1 and coercive force H1, the 2nd magnetic layer 2 having a Curie point T2 and coercive force H2 and the 3rd magnetic layer having a Curie point T3 and coercive force H3 on the substrate B. The respective magnetic layers are made of the alloy of rare earths and transition metals and have H1>H3>H2 T3>T1>T2. These layers satisfy the conditions expressed by equation I when the apparent magnetic wall energies of the 1st magnetic layer and the 3rd magnetic layer appearing through the 2nd magnetic layer are designated as deltaw13, and the film thicknesses of the 1st magnetic layer and the 3rd magnetic layer are successively designated as h1, h3. A magnetic field generating means is provided on the position separate from a recording head and recording is executed by binary laser power at the time of recording. The good over writing is thereby enabled. |
