PERPENDICULAR MAGNETIC RECORDING MEDIUM

• Main Author: TANUMA TOSHIO
• Format: Patent
• Language: English
• Published: 23.06.1992
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PURPOSE:To provide a reproduction characteristic excellent over long and short wavelength areas by setting the relative existence ratio of oxygen element at a lower layer portion of a magnetic recording layer larger than that at a surface layer portion thereof and setting the magnitude of the saturated flux density of the magnetic recording layer within a specified range. CONSTITUTION:In a magnetic recording layer, a relative existence ratio of oxygen element is made larger at a lower portion thereof than at a surface layer portion while a saturated flux density of the magnetic recording layer is set within a range of 3,000-7,000 Gauss. In other words, an output characteristic is improved in a high frequency area by the larger relative existence of the oxygen element at the lower layer part of the magnetic recording layer than at a surface portion thereof. Moreover, when the magnitude of the saturated flux density of the magnetic recording layer is within a range of 3,000-7,000 Gauss, cracking of a magnetic recording layer can be checked as caused by a difference in degree of oxidization between the surface layer part and the lower layer part of the magnetic thin film. This provides excellent output characteristic over long and short wavelength areas and achieves a higher durability.