Magnetic recording medium and magnetic storage apparatus
View Patent ↗A magnetic recording medium includes a substrate, an AlFe-based alloy layer provided above the substrate, an underlayer provided on the AlFe-based alloy layer, and a recording layer provided on the underlayer and magnetized in a predetermined recording direction when being recorded with information. The substrate has a textured surface having grooves formed approximately along the recording direction.
1. A magnetic recording medium comprising:
a substrate;
an AlFe-based alloy layer provided above the substrate;
an underlayer provided on the AlFe-based alloy layer; and
a recording layer, provided on the underlayer, and magnetized in a predetermined recording direction when being recorded with information,
wherein the substrate has a textured surface having grooves formed approximately along the recording direction, and
wherein the AlFe-based alloy layer is made of AlFe having a Fe atomic concentration in a range of 30 at. % to 40 at. %,
wherein sublattices SL- 1 and SL- 2 of the AlFe are distorted.
2. The magnetic recording medium as claimed in claim 1 , further comprising:
a seed layer, made of an amorphous material, provided between the substrate and the AlFe-based alloy layer.
3. The magnetic recording medium as claimed in claim 1 , further comprising:
a seed layer, made of a material that is other than AlFe-based alloys and has a B2 crystal structure, provided immediately under the AlFe-based alloy layer.
4. The magnetic recording medium as claimed in claim 3 , wherein the seed layer is made of an AlRu alloy or a NiAl alloy.
5. The magnetic recording medium as claimed in claim 1 , wherein the substrate has a disk shape, and the textured surface is textured in a circumferential direction of the disk shape.
6. The magnetic recording medium as claimed in claim 1 , wherein the AlFe-based alloy layer has a thickness in a range of 2 nm to 100 nm.
7. The magnetic recording medium as claimed in claim 1 , further comprising:
a nonmagnetic intermediate layer, provided between the underlayer and the recording layer, and made of a Co—X3 alloy, where X3=Cr, Ta Mo, Mn, Re, Ru or an alloy thereof.
8. The magnetic recording medium as claimed in claim 1 , wherein the recording layer comprises:
a first magnetic layer provided on the underlayer;
a nonmagnetic coupling layer provided on the first magnetic layer; and
a second magnetic layer provided on the nonmagnetic coupling layer,
wherein the first and second magnetic layers are antiferromagnetically exchange-coupled via the nonmagnetic coupling layer such that magnetizations of the first and second magnetic layers are mutually antiparallel in a state where no external magnetic field is applied on the magnetic recording medium.
9. The magnetic recording medium as claimed in claim 8 , wherein the first magnetic layer and/or the second magnetic layer is made of a CoCr-M1 alloy, where M1=Pt, B, Ta, Ni, Cu, Ag, Pd, Si, C, Fe, Re, Nb, Hf or an alloy thereof.
10. A magnetic recording medium comprising:
a substrate;
a texturing layer provided on the substrate;
an AlFe-based alloy layer provided above the texturing layer;
an underlayer provided on the AlFe-based alloy layer; and
a recording layer, provided on the underlayer, and magnetized in a predetermined recording direction when being recorded with information,
wherein the texturing layer has a textured surface having grooves formed approximately along the recording direction, and
wherein the AlFe-based alloy layer is made of AlFe having a Fe atomic concentration in a range of 30 at. % to 40 at. %,
wherein sublattices SL- 1 and SL- 2 of the AlFe are distorted.
11. The magnetic recording medium as claimed in claim 10 , further comprising:
a seed layer, made of an amorphous material, and provided between the texturing layer and the AlFe-based alloy layer.
12. The magnetic recording medium as claimed in claim 11 , wherein the seed layer is made of a material selected from a group consisting of CoW, CrTi and NiP.
13. The magnetic recording medium as claimed in claim 10 , further comprising:
a seed layer, made of a material that is other than AlFe-based alloys and has a B2 crystal structure, provided immediately under the AlFe-based alloy layer.
14. The magnetic recording medium as claimed in claim 13 , wherein the seed layer is made of an AlRu alloy or a NiAl alloy.
15. The magnetic recording medium as claimed in claim 10 , wherein the substrate has a disk shape, and the textured surface is textured in a circumferential direction of the disk shape.
16. The magnetic recording medium as claimed in claim 10 , wherein the AlFe-based alloy layer has a thickness in a range of 2 nm to 100 nm.
17. The magnetic recording medium as claimed in claim 10 , further comprising:
a nonmagnetic intermediate layer, provided between the underlayer and the recording layer, and made of a Co—X3 alloy, where X3=Cr, Ta Mo, Mn, Re, Ru or an alloy thereof.
18. The magnetic recording medium as claimed in claim 10 , wherein the recording layer comprises:
a first magnetic layer provided on the underlayer;
a nonmagnetic coupling layer provided on the first magnetic layer; and
a second magnetic layer provided on the nonmagnetic coupling layer,
wherein the first and second magnetic layers are antiferromagnetically exchange-coupled via the nonmagnetic coupling layer such that magnetizations of the first and second magnetic layers are mutually antiparallel in a state where no external magnetic field is applied on the magnetic recording medium.
19. The magnetic recording medium as claimed in claim 18 , wherein the first magnetic layer and/or the second magnetic layer is made of a CoCr-M1 alloy, where M1=Pt, B, Ta, Ni, Cu, Ag, Pd, Si, C, Fe, Re, Nb, Hf or an alloy thereof.
20. A magnetic storage apparatus comprising:
at least one magnetic recording medium; and
a head configured to record information on and reproduce information from the magnetic recording medium,
wherein the magnetic recording medium comprises a substrate, an AlFe-based alloy layer provided above the substrate, an underlayer provided on the AlFe-based alloy layer, and a recording layer provided on the underlayer and magnetized in a predetermined recording direction when being recorded with information, and
the substrate has a textured surface having grooves formed approximately along the recording direction, and
wherein the AlFe-based alloy layer is made of AlFe having a Fe atomic concentration in a range of 30 at. % to 40 at. %,
wherein sublattices SL- 1 and SL- 2 of the AlFe are distorted.
21. A magnetic storage apparatus comprising:
at least one magnetic recording medium; and
a head configured to record information on and reproduce information from the magnetic recording medium,
wherein the magnetic recording medium comprises a substrate, a texturing layer provided on the substrate, an AlFe-based alloy layer provided above the texturing layer, an underlayer provided on the AlFe-based alloy layer, and a recording layer provided on the underlayer and magnetized in a predetermined recording direction when being recorded with information, and
the texturing layer has a textured surface having grooves formed approximately along the recording direction, and
wherein the AlFe-based alloy layer is made of AlFe having a Fe atomic concentration in a range of 30 at. % to 40 at. %,
wherein sublattices SL- 1 and SL- 2 of the AlFe are distorted.