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AssigneeFuji Electric Co., Ltd.
InventorsHiroyuki Uwazumi, Yasushi Sakai, Tadaaki Oikawa, Miyabi Nakamura
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A perpendicular magnetic recording medium has a granular magnetic layer and a nonmagnetic underlayer of a metal or an alloy having a hexagonal close packed (hcp) crystal structure. A seed layer of a metal or an alloy of a face-centered cubic (fcc) crystal structure is provided under the nonmagnetic underlayer. Such a perpendicular magnetic recording medium exhibits excellent magnetic characteristics even when the thickness of the underlayer or the total thickness of the underlayer and the seed layer is very thin. Excellent magnetic characteristics can be obtained even when of the substrate is not preheated. Accordingly, a nonmagnetic substrate, such as a plastic resin can be employed to reduce the manufacturing cost.
A perpendicular magnetic recording medium comprising:
A method of manufacturng a perpendicular magnetic recording medium comprising a nonmagnetic substrate and at least a seed layer, a nonmagnetic underlayer, a magnetic layer, and a protective film sequentially laminated on said substrate, wherein said magnetic layer is composed of ferromagnetic crystal grains and nonmagnetic grain boundaries mainly composed of silicon oxide, wherein said nonmagnetic underlayer is composed of a metal or an alloy having a hexagonal close packed crystal structure, wherein said metal is selected from a group consisting of Re, Ru, and Os and said alloy composing said nonmagnetic underlayer contains at least one element selected from a group consisting of Re, Ru, and Os, and wherein the seed layer is composed of a metal or an alloy having a face-centered cubic crystal structure,the method comprising the steps of:
Dependencies are inferred from the claim text.