Magnetic recording medium and method for manufacturing same
First Claim
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1. A magnetic recording medium comprising:
- a non-magneticmagnetic under-layer, a magnetic layer, a protective film, and a liquid lubricant layer sequentially laminated on a non-magneticmagnetic substrate, wherein said magnetic layer has a layered structure including at least two magnetic layer components, each of said magnetic layer components having ferromagnetic grains and non-magneticmagnetic grain boundaries surrounding said ferromagnetic grains.
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Abstract
A magnetic recording medium has a non-magnetic under-layer, a magnetic layer, a protective film and a liquid lubricant layer sequentially laminated on a non-magnetic substrate. The magnetic layer has a multi-layer structure laminated with two or more magnetic layer components, each of the magnetic layer components having ferromagnetic grains and non-magnetic grain boundaries surrounding the grain. The resulting magnetic recording medium has a granular magnetic layer exhibiting very high Hc accompanying high density of magnetic recording, while decreasing the amount of platinum needed for attaining the high Hc, and reducing media noise accompanying the high recording density.
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Citations
15 Claims
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1. A magnetic recording medium comprising:
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a non-magneticmagnetic under-layer, a magnetic layer, a protective film, and a liquid lubricant layer sequentially laminated on a non-magneticmagnetic substrate, wherein said magnetic layer has a layered structure including at least two magnetic layer components, each of said magnetic layer components having ferromagnetic grains and non-magneticmagnetic grain boundaries surrounding said ferromagnetic grains. - View Dependent Claims (2, 3, 4, 5)
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6. A magnetic recording medium comprising:
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a non-magneticmagnetic under-layer, a magnetic layer, a protective film, and a liquid lubricant layer sequentially laminated on a non-magneticmagnetic substrate, wherein said magnetic layer includes at least two magnetic layer components and at least three oxide layers; and
said magnetic layer components and said oxide layers are alternately disposed such that a top layer and a bottom layer in said magnetic layer are two of said at least three oxide layers. - View Dependent Claims (7, 8, 9, 10)
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11. A method for manufacturing a magnetic recording medium comprising:
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laminating a non-magneticmagnetic under-layer on a non-magneticmagnetic substrate;
laminating a magnetic layer on said under-layer by depositing a plurality of magnetic layer components, each of said magnetic layer components comprising ferromagnetic grains and grain boundaries surrounding said grains;
laminating a protective film on said magnetic layer; and
laminating a liquid lubricant layer on said protective film. - View Dependent Claims (12, 13, 15)
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14. A method for manufacturing a magnetic recording medium comprising:
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laminating a non-magneticmagnetic under-layer on a non-magneticmagnetic substrate;
laminating a magnetic layer on said under-layer by (i)exposing to an atmosphere of oxygen-containing gas and forming an oxide layer on a surface, (ii) depositing a magnetic layer component comprising ferromagnetic grains and grain boundaries surrounding said grains, (iii) repeating the procedures (i) and (ii) predetermined times, and (iv) exposing to said atmosphere of oxygen-containing gas and forming an oxide layer on a surface;
laminating a protective film on said magnetic layer; and
laminating a liquid lubricant layer on said protective film.
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Specification