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US 6,713,197 B2Granted
Perpendicular magnetic recording medium and magnetic recording apparatus
AssigneeKabushiki Kaisha Toshiba
InventorsFutoshi Nakamura, Takashi Hikosaka, Soichi Oikawa, Hideo Ogiwara
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Abstract
A soft magnetic laminate layer is arranged between a nonmagnetic substrate and a perpendicular magnetic recording layer so as to provide a perpendicular magnetic recording medium low in noise and capable of a high density recording. The soft magnetic laminate layer comprises a soft magnetic layer having a thickness not larger than 500 Å and a nonmagnetic layer, comprises a first soft magnetic layer and a second soft magnetic layer differing from the first soft magnetic layer in the crystal structure, or comprises a layer of a granular structure consisting of magnetic particles and a nonmagnetic matrix and a soft magnetic layer.
Claims18
A magnetic recording medium comprising:
- a nonmagnetic substrate;
- a perpendicular magnetic recording layer for recording signal;
- and
- a soft magnetic laminate layer formed between said nonmagnetic substrate and said perpendicular magnetic recording layer for recording signal, and including at least two soft magnetic layers and a nonmagnetic layer interposed therebetween, each of said soft magnetic layers having a thickness not larger than 500 Å, wherein the value of the saturation magnetization per layer of said soft magnetic layer is not larger than 90% of the saturation magnetization value under a bulk state.
1 more element
A magnetic recording medium comprising:
- a nonmagnetic substrate;
- a perpendicular magnetic recording layer;
- and
- a soft magnetic laminate layer formed between the nonmagnetic substrate and the perpendicular magnetic medium, and including a soft magnetic granular layer formed of a nonmagnetic matrix and soft magnetic metal particles dispersed in said matrix, and a soft magnetic layer.
1 more element
A magnetic recording apparatus, comprising:
- a magnetic recording medium having a nonmagnetic substrate, a perpendicular magnetic recording layer for recording signal, and a soft magnetic laminate layer formed between said nonmagnetic substrate and said perpendicular magnetic recording layer for recording signal, and including at least two soft magnetic layers and a nonmagnetic layer interposed therebetween, each of said soft magnetic layers having a thickness not larger than 500 Å;
- driving means supporting and rotating the perpendicular magnetic recording medium;
- a magnetic head including an element for recording information in the perpendicular magnetic recording medium and another element for reading the recorded information;
- and
- a carriage assembly supporting the magnetic head such that the magnetic head is movable relative to the magnetic recording medium,
- wherein the value of the saturation magnetization per layer of said soft magnetic layer is not larger than 90% of the saturation magnetization value under a bulk state.
3 more elements
A magnetic recording apparatus comprising:
- a magnetic recording medium having a nonmagnetic substrate,
- a perpendicular magnetic recording layer,
- a soft magnetic laminate layer formed between the nonmagnetic substrate and the perpendicular magnetic medium, and including a soft magnetic granular layer formed of a nonmagnetic matrix and soft magnetic metal particles dispersed in said matrix, and a soft magnetic layer;
- driving means supporting and rotating the perpendicular magnetic recording medium;
- a magnetic head including an element for recording information in the perpendicular magnetic recording medium and another element for reading the recorded information;
- and
- a carriage assembly supporting the magnetic head and making the magnetic head be movable relative to the magnetic recording medium.
4 more elements
A magnetic recording medium comprising:
- a nonmagnetic substrate;
- a perpendicular magnetic recording layer for recording signal;
- and
- a soft magnetic laminate layer formed between said nonmagnetic substrate and said perpendicular magnetic recording layer for recording signal, and including at least two soft magnetic layers and a nonmagnetic layer interposed therebetween, each of said soft magnetic layers having a thickness not larger than 500 Å, wherein said perpendicular magnetic recording layer is formed of at least one layer of a Co—Pt—Cr—O series magnetic thin film.
1 more element
A magnetic recording apparatus, comprising:
- a magnetic recording medium having a nonmagnetic substrate, a perpendicular magnetic recording layer for recording signal, and a soft magnetic laminate layer formed between said nonmagnetic substrate and said perpendicular magnetic recording layer for recording signal, and including at least two soft magnetic layers and a nonmagnetic layer interposed therebetween, each of said soft magnetic layers having a thickness not larger than 500 Å;
- driving means supporting and rotating the perpendicular magnetic recording medium;
- a magnetic head including an element for recording information in the perpendicular magnetic recording medium and another element for reading the recorded information;
- and
- a carriage assembly supporting the magnetic head such that the magnetic head is movable relative to the magnetic recording medium, wherein said perpendicular magnetic recording layer is formed of at least one layer of a Co—Pt—Cr—O series magnetic thin film.
2 more elements
Dependencies are inferred from the claim text.