PURPOSE: To improve the durability and productivity of the titled vertical magnetic recording medium by providing cobalt oxide on the vertical magnetic recording layer with an opposed target system sputtering method in an oxidizing gas atmosphere.
CONSTITUTION: A high-permeability metallic thin layer 2 consisting of an nickel- iron alloy and a vertical magnetic recording layer 3 consisting of a cobalt- chromium alloy thin film are successively laminated on both surfaces of a substrate 1 of a polyethylene terephthalate film by using an opposed target system sputtering device to obtain a both-faces 2 layered medium. Both targets are composed of metallic cobalt, an oxidizing gaseous mixture of argon and oxygen contg. 10W50vol% oxygen is introduced into a vacuum vessel from a gas introducing system and the gas pressure during sputtering is kept at 0.5W2.5pa. Electric power enough to obtain the desired sputtering speed and film characteristic is impressed on the targets to form a protective layer 4 on the both-faces 2-layered medium and a vertical magnetic recording medium having a metallic luster is obtained.
YATABE TOSHIAKI
MATSUZAWA HIROSHI
| JPS59215025A | 1984-12-04 | |||
| JPS5841439A | 1983-03-10 |
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