| 摘要 |
PURPOSE:To obtain a magnetic recording medium which is improved in the crystal orientation and magnetic characteristics of a magnetic medium layer and is increases in the number of times of CSS by providing a specific nonmagnetic underlying layer on a nonmagnetic substrate via a nonmagnetic hardened layer and forming the ferromagnetic medium layer on the nonmagnetic underlying layer. CONSTITUTION:The nonmagnetic hardened film 2 such as alumite film is coated on the nonmagnetic substrate 1 consisting of an Al alloy, etc. and the surface is finished to a specular surface to improve the surface hardness and accuracy of the substrate 1. Either of SiC or Si3N4 is then formed by a reactive sputtering method, etc. on the film 2 to a range of 50-2,400Angstrom film thickness to provide the nonmagnetic underlying layer 3. The magnetic medium layer 4 consisting of gamma-Fe2O3, Co or Co alloy, etc. is formed on the layer 3, by which the magnetic recording medium is obtd. The crystal orientation of the layer 4 is made higher by providing the layer 3 than in the case of forming directly the magnetic medium layer 4 on the layer 2. The high reliability magnetic disk which has the good magnetic characteristics and squareness ratio and can increase the number of times of CSS is thus obtd.
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