Claims
- 1. A magnetic recording medium comprising:
- an underlayer formed on a substrate and made of a material containing vanadium as a main constituent, and
- a magnetic film formed on said underlayer and made of CoPtO-based alloy, wherein said magnetic film has a crystalline phase and an amorphous phase containing oxygen in a larger amount than that in said crystalline phase.
- 2. A medium according to claim 1, wherein a material constituting said substrate is lattice-matched with the CoPtO-based alloy through said underlayer.
- 3. A medium according to claim 1, wherein a magnetization amount v.multidot.I.sub.sb of said magnetic film satisfies 0<v.multidot.I.sub.sb .ltoreq.0.3.times.10.sup.-14 emu.
- 4. A medium according to claim 3, wherein a ratio (Mr.multidot.t/v.multidot.I.sub.sb) of a product Mr.multidot.t of a residual magnetization amount of said magnetic film in planar and a thickness of said magnetic film to the magnetization amount v.multidot.I.sub.sb of said magnetic film is not less than 3.5.times.10.sup.11 particles/cm.sup.2.
- 5. A medium according to claim 1, wherein a ratio Hc/(Mr.multidot.t) of a coercive force Hc to a product Mr.multidot.t of a residual magnetization amount of said magnetic film in planar and a thickness of said magnetic film is at least 6,000.
- 6. A medium according to claim 1, wherein a thickness of said magnetic film is not more than 15 nm, and a coercive force rectangularity ratio S* of said magnetic film in planar is 0.4 to 0.82.
- 7. A medium according to claim 1, wherein said magnetic film has a magnetic anisotropy in planar.
- 8. A magnetic medium according to claim 1, wherein the CoPtO-based alloy constituting said magnetic film contains at least 10 atomic % of oxygen.
- 9. A magnetic recording medium comprising a first underlayer formed on a substrate and made of a crystal having a crystal structure for forming a body-centered cubic lattice, a second underlayer formed on said first underlayer and made of an amorphous material, and a magnetic film formed on said second underlayer and made of a CoPtO-based alloy.
- 10. A medium according to claim 9, wherein said first underlayer is formed on said substrate to form a plurality of islands.
- 11. A medium according to claim 9, wherein a material constituting said first underlayer contains at least one element selected from the group consisting of niobium, vanadium, and chromium.
- 12. A medium according to claim 9, wherein a material constituting said second underlayer contains at least one material selected from the group consisting of carbon, boron, boron nitride, and silicon dioxide.
- 13. A magnetic recording medium comprising:
- an underlayer formed on a substrate;
- a plurality of magnetic films made of a CoPtO-based alloy and laminated on said underlayer; and
- an interlayer respectively provided between each of said magnetic films laminated,
- wherein said underlayer and said interlayer(s) are made of vanadium or an alloy mainly containing vanadium, and
- wherein each of said magnetic films has a crystalline phase and an amorphous phase containing oxygen in a larger amount than that in said crystalline phase.
- 14. A medium according to claim 13, wherein said CoPtO-based alloy contains 5 to 45 atomic % of oxygen.
- 15. A medium according to claim 13, wherein said CoPtO-based alloy contains 45 to 85 atomic % of Co and 10 to 40 atomic % of Pt.
- 16. A medium according to claim 13, wherein at least one of said underlayer and said interlayer(s) is made of vanadium.
- 17. A medium according to claim 13, wherein at least one of said underlayer and said interlayer(s) is made of an alloy containing at least 30 atomic % of vanadium.
- 18. A medium according to claim 13, wherein at least one of said underlayer and said interlayer(s) is made of an alloy mainly containing vanadium, and said alloy contains a material selected form the group consisting of niobium, titanium, tantalum and mixtures thereof.
- 19. A medium according to claim 13, wherein a thickness of said magnetic films is 5 to 20 nm.
- 20. A magnetic recording medium comprising:
- an underlayer formed on a substrate;
- a plurality of magnetic films made of a CoPtO-based alloy and laminated on said underlayer; and
- an interlayer respectively provided between each of said magnetic films laminated,
- wherein said underlayer and said interlayer(s) are made of vanadium or an alloy mainly containing vanadium, at least one of said underlayer and said interlayer(s) is made of an alloy mainly containing vanadium, and said alloy contains a material selected form the group consisting of niobium, titanium, tantalum and mixtures thereof.
- 21. A medium according to claim 20, wherein said CoPtO-based alloy contains 5 to 45 atomic % of oxygen.
- 22. A medium according to claim 20, wherein said CoPtO-based alloy contains 45 to 85 atomic % of Co and 10 to 40 atomic % of Pt.
- 23. A medium according to claim 20, wherein at least one of said underlayer and said interlayer(s) is made of vanadium.
- 24. A medium according to claim 20, wherein at least one of said underlayer and said interlayer(s) is made of an alloy containing at least 30 atomic % of vanadium.
- 25. A medium according to claim 20, wherein a thickness of said magnetic films is 5 to 20 nm.
Priority Claims (2)
Number |
Date |
Country |
Kind |
7-234353 |
Sep 1995 |
JPX |
|
9-056259 |
Mar 1997 |
JPX |
|
Parent Case Info
This application is a continuation-in-part of U.S. patent application Ser. No. 08/713,202, filed Sep. 12, 1996, now abandoned, the entire contents of which are incorporated herein by reference.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4652499 |
Howard |
Mar 1987 |
|
5051288 |
Ahlert et al. |
Sep 1991 |
|
5066552 |
Howard et al. |
Nov 1991 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
713202 |
Sep 1996 |
|