Magnetic recording medium
AssigneeTDK Corporation
InventorsMasatoshi Nakayama, Koji Kobayashi, Kunihiro Ueda, Mitsuru Takai, Shigeo Kurose
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Abstract
A magnetic recording medium comprising a ferromagnetic metal thin film comprised predominantly of cobalt on a substrate is improved in durability and performance by forming the ferromagnetic metal thin film as a multi-layered structure including at least two layers, one or both of which contain an organic polymer. A plasma-polymerized film may be provided as an interlayer between the layers of the metal thin film or as a topcoat.
Claims24
In a magnetic recording medium comprising a plastic substrate and a ferromagnetic metal thin film comprised predominately of cobalt on the substrate,
- the improvement wherein said ferromagnetic metal thin film has a multi-layered structure including at least two layers, a lowermost layer adjoining the substrate and an uppermost layer remote from the substrate, at least one of which contains carbon, wherein the quotient C2/C1 is up to 0.3 provided that the lowermost layer has an oxygen concentration C2 at its interface with said substrate and the uppermost layer has an oxygen concentration C1 at its surface remote from said substrate.
In a magnetic recording medium comprising a plastic substrate and a ferromagnetic metal thin film comprised predominately of cobalt on the substrate,
- the improvement wherein said ferromagnetic metal thin film has a multi-layered structure including at least two layers, a lowermost layer adjoining the substrate and an uppermost layer remote from the substrate, at least on of which contains carbon, and wherein the quotient C3/C1 ranges from 0.1-3.0 provided that a layer directly adjoining the uppermost layer has an oxygen concentration C3 at its interface with said uppermost layer and the uppermost layer has an oxygen concentration C1 at its surface remote from said substrate.
Dependencies are inferred from the claim text.