Vertical recording medium with thin soft magnetic film
AssigneeNEC Corporation
InventorHirotaka Hokkyo
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Abstract
A vertical magnetic recording medium includes a soft magnetic film formed on a substrate, and a vertical magnetization film formed on the soft magnetic film. μ·δb≧1000, when μ is a permeability of the soft magnetic film, and δb [nm] is a film thickness of the soft magnetic film. The permeability μ of the soft magnetic film is 5≦μ≦200, and the film thickness δb of the soft magnetic film is equal to or less than 500 nm. Also, vertical magnetic anisotropy energy Ku [erg/cc] of the vertical magnetization film is 1×107≦Ku≦7×108, and coercive force Hc [kOe] of the vertical magnetization film in the vertical direction to a surface of the vertical magnetization film is 5≦Hc≦10.
Claims9
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film, and
- wherein vertical magnetic anisotropy energy Ku of said vertical magnetization film is 1×107≦Ku≦7×108.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film, and
- wherein coercive force Hc of said vertical magnetization film in the vertical direction to a surface of said vertical magnetization film is 5≦Hc≦10.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film, and
- wherein said vertical magnetization film comprises RCo alloy, where R is one or more selected from the group consisting of Y, Ce, Sm, La and Pr.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000, where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film,
- wherein said soft magnetic film comprises CoNiFe alloy, and
- wherein said soft magnetic film comprises 62at %Co-12at %Ni-26at %Fe alloy.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film,
- said permeability μ of said soft magnetic film is 5≦μ≦200,
- said film thickness δb of said soft magnetic film is equal to or less than 500 nm, and
- wherein said vertical magnetization film comprises RCo alloy, where R is one or more selected from the group consisting of Y, Ce, Sm, La and Pr.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film,
- said permeability μ of said soft magnetic film is 5≦μ≦200,
- said film thickness δb of said soft magnetic film is equal to or less than 500 nm, and
- wherein vertical magnetic anisotropy energy Ku of said vertical magnetization film is 1×107≦Ku≦7×108.
A vertical magnetic recording medium comprising:
- a soft magnetic film formed on a substrate;
- and
- a vertical magnetization film formed on said soft magnetic film,
- wherein μ·δb≧1000 where μ is a permeability of said soft magnetic film, and δb is a film thickness of said soft magnetic film,
- said permeability μ of said soft magnetic film is 5≦μ≦200,
- said film thickness δb of said soft magnetic film is equal to or less than 500 nm, and
- wherein coercive force Hc of said vertical magnetization film in the vertical direction to a surface of said vertical magnetization film is 5≦Hc≦10.
Dependencies are inferred from the claim text.