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US 2003/0170499 A1Published application
Magnetic recording medium and magnetic storage apparatus
AssigneeFujitsu Limited
InventorIwao Okamoto
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium has first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium, with a first nonmagnetic layer interposed between the first and second magnetic layers and a second nonmagnetic layer interposed between the second and third magnetic layers. A relationship Ms2×t2<(Ms1×t1+Ms3×t3) stands, where Ms1, Ms2 and Ms3, and t1, t2 and t2 respectively denote saturation magnetizations and thicknesses of the first, second and third magnetic layers.
Claims19
A magnetic recording medium comprising:
- a first magnetic layer having a saturation magnetization Ms1 and a thickness t1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a saturation magnetization Ms2 and a thickness t2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a saturation magnetization Ms3 and a thickness t3,
- said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein Ms2×t2<(Ms1×t1+Ms3×t3).
5 more elements
A magnetic recording medium comprising:
- a first magnetic layer having a saturation magnetization Ms1 and a thickness t1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a saturation magnetization Ms2 and a thickness t2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a saturation magnetization Ms3 and a thickness t3, said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein |Ms1×t1−Ms3×t3|/(Ms1×t1+Ms3×t3)/2<0.3.
4 more elements
A magnetic recording medium comprising:
- a first magnetic layer having a coercivity Hc1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a coercivity Hc2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a coercivity Hc3,
- said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein Hc2<Hc1 and Hc2<Hc3.
5 more elements
A magnetic recording medium comprising:
- a first magnetic layer having a coercivity Hc1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a coercivity Hc2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a coercivity Hc3,
- said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein |Hc1−Hc3|/(Hc1+Hc3)/2<0.3.
5 more elements
A magnetic storage apparatus comprising:
- one or a plurality of magnetic recording media;
- and
- recording and/or reproducing means for recording information to and/or reproducing information from said one or plurality of magnetic recording media,
- each magnetic recording medium comprising:
- a first magnetic layer having a saturation magnetization Ms1 and a thickness t1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a saturation magnetization Ms2 and a thickness t2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a saturation magnetization Ms3 and a thickness t3,
- said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein Ms2×t2<(Ms1×t1+Ms3×t3).
9 more elements
A magnetic storage apparatus comprising:
- one or a plurality of magnetic recording media;
- and
- recording and/or reproducing means for recording information to and/or reproducing information from said one or plurality of magnetic recording media, each magnetic recording medium comprising:
- a first magnetic layer having a saturation magnetization Ms1 and a thickness t1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a saturation magnetization Ms2 and a thickness t2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a saturation magnetization Ms3 and a thickness t3, said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein |Ms1×t1−Ms3×t3|/(Ms1×t1+Ms3×t3)/2<0.3.
7 more elements
A magnetic storage apparatus comprising:
- one or a plurality of magnetic recording media;
- and
- recording and/or reproducing means for recording information to and/or reproducing information from said one or plurality of magnetic recording media, each magnetic recording medium comprising:
- a first magnetic layer having a coercivity Hc1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a coercivity Hc2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a coercivity Hc3, said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein Hc2<Hc1 and Hc2<Hc3.
7 more elements
A magnetic storage apparatus comprising:
- one or a plurality of magnetic recording media;
- and
- recording and/or reproducing means for recording information to and/or reproducing information from said one or plurality of magnetic recording media, each magnetic recording medium comprising:
- a first magnetic layer having a coercivity Hc1;
- a first nonmagnetic layer provided on said first magnetic layer;
- a second magnetic layer, provided on said first nonmagnetic layer, having a coercivity Hc2;
- a second nonmagnetic layer provided on said second magnetic layer;
- and
- a third magnetic layer, provided on said second nonmagnetic layer, having a coercivity Hc3, said first, second and third magnetic layers having magnetization directions which are alternately antiparallel in a state where no external magnetic field is applied on the magnetic recording medium,
- wherein |Hc1−Hc3|/(Hc1+Hc3)/2<0.3.
7 more elements
Dependencies are inferred from the claim text.