| 摘要 |
PURPOSE:To reduce overall film thickness greatly and perform recording and reproduction effectively even when the film thickness is reduced as mentioned above by forming a cobalt film and a cobalt-chromium alloy film on a nonmagnetic substrate successively by sputtering. CONSTITUTION:For the nonmagnetic material substrate 1 of a flexible disk, there is used a heat-resistant high polymer film of about 70mum in thickness which secures a stable run of the disk and has adequate rigidity for obtaining the contacting between the disk and a magnetic disk all the time; a magnetic layer 2 made of a cobalt film is formed on one surface of this substrate 1 by sputtering to a 1,000-5,000Angstrom thickness, and a vertically magnetized film layer 3 made of the cobalt-chromium alloy film is formed thereupon by sputtering as well to about 8,000Angstrom for example, thus realizing so-called double-layered structure characteristic to a vertical magnetic recording medium. This is punched into a disk of 20cm diameter for example, to obtain flexible disks which are practically usable. |
