Perpendicular magnetic recording medium
AssigneeFuji Electric Co., Ltd.
InventorsAkira Sato, Shunji Takenoiri, Yasushi Sakai
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Abstract
A perpendicular magnetic recording medium, which includes a first magnetic recording layer, a second magnetic recording layer, and a third magnetic recording layer disposed sequentially on a nonmagnetic substrate, and a coupling layer formed between the first and second magnetic recording layers. The first, second and third magnetic recording layers have an easy axis of magnetization in a direction perpendicular to a film plane of the nonmagnetic substrate. The first and second magnetic recording layers are ferromagnetically coupled via the coupling layer.
Claims18
A perpendicular magnetic recording medium, comprising:
- a first magnetic recording layer, a second magnetic recording layer, and a third magnetic recording layer disposed sequentially on a nonmagnetic substrate, the first, second and third magnetic recording layers having an easy axis of magnetization in a direction perpendicular to a film plane of the nonmagnetic substrate;
- and
- a coupling layer formed between the first and second magnetic recording layers, the first and second magnetic recording layers being ferromagnetically coupled via the coupling layer, wherein
- the third magnetic recording layer is coupled with the second magnetic recording layer, with no coupling layer formed therebetween;
- the first and second magnetic recording layers have a granular structure, in which magnetic crystal grains are dispersed in a matrix of nonmagnetic oxides or nonmagnetic nitrides;
- and
- the first, second and third magnetic recording layers respectively have a uniaxial anisotropy constant Ku1, Ku2 and Ku3, where Ku1>Ku2>Ku3.
A perpendicular magnetic recording medium, comprising:
- a first magnetic recording layer, a second magnetic recording layer, and a third magnetic recording layer disposed sequentially on a nonmagnetic substrate, the first, second and third magnetic recording layers having an easy axis of magnetization in a direction perpendicular to a film plane of the nonmagnetic substrate;
- and
- a coupling layer formed between the first and second magnetic recording layers, the first and second magnetic recording layers being ferromagnetically coupled via the coupling layer, wherein
- the third magnetic recording layer is coupled with the second magnetic recording layer, with no coupling layer formed therebetween;
- and
- the first, second and third magnetic recording layers respectively have a uniaxial anisotropy constant Ku1, Ku2 and Ku3, where Ku1>Ku2>Ku3.
Dependencies are inferred from the claim text.