MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a vertical magnetic recording medium which has high mechanical/chemical stability and high density by forming the continuous magnetic layers containing mainly iron oxide over 2 surfaces of a substrate with a specific ratio set between the intra-surface residual magnetization and the vertical residual magnetization. CONSTITUTION:Continuous magnetic layers 12 and 13 containing mainly iron oxide such as Fe3O4, etc. are formed on both sides of a film type substrate 6, for example. Then two pairs of counter targets T1 and T2 are provided within a vacuum tank of a counter target sputtering device. The continuous magnetic layers are formed at a time on both sides of the substrate 6 while the substrate 6 is sent to a take-up roll 32 from a feed roll 31 via a guide roll 30. This film type magnetic recording medium has a large width and cut into a disk form to obtain a floppy disk. Thus it is possible to obtain a magnetic recording medium having excellent vertical magnetization characteristics and high corrosion resistance with >=0.5 MV/MH ratio between the intra-surface and vertical residual magnetizations for layers 12 and 13.