Perpendicular magnetic recording media with thin soft magnetic underlayers and recording systems comprising same

• US 20080131734A1
• Filed: 12/01/2006
• Published: 06/05/2008
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Rou, Shanghsien, Liu, Connie Chunling, Xue, Jianhua, Tang, Li, Lee, Li-Lien, Xu, Weilu, Zheng, Youfeng
• Granted Patent: US 8,465,854 B2
• Time in Patent Office: Days
• US Class Current: 428/829
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/65 characterised by its composition G11B5/66 takes precedence
• CPC Class Codes: G11B 5/66 the record carriers consisting of several layers
• CPC Class Codes: G11B 5/667 including a soft magnetic layer
• CPC Class Codes: G11B 5/672 having different compositions in a plurality of magnetic layers, e.g. layer compositions having differing elemental components or differing proportions of elements
• CPC Class Codes: G11B 5/674 having differing macroscopic or microscopic structures, e.g. differing crystalline lattices, varying atomic structures or differing roughnesses
• CPC Class Codes: G11B 5/7368 Non-polymeric layer under the lowermost magnetic recording layer base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/7373 Non-magnetic single underlayer comprising chromium

Abstract

A perpendicular magnetic recording medium comprises a non-magnetic substrate having a surface; and a plurality of overlying thin film layers forming a layer stack on the substrate surface, the layer stack including a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL), the SUL having a thickness of up to about 100 Å. Also disclosed is a data/information recording, storage, and retrieval system comprising the perpendicular magnetic recording medium and a single-pole magnetic transducer head including main and auxiliary poles positioned in spaced adjacency to an upper surface of the layer stack, the single-pole transducer head comprising a front shield adjacent the main pole.

Claims

1. A perpendicular magnetic recording medium, comprising:

(a) a non-magnetic substrate having a surface; and

(b) a plurality of overlying thin film layers forming a layer stack on said substrate surface, said layer stack including a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL),

wherein said perpendicular magnetic recording medium has only one SUL, and said SUL has a thickness up to about 100 Å

.

2. The medium as in claim 1, wherein:

said magnetically hard perpendicular magnetic recording layer structure comprises a multilayer structure.

3. The medium as in claim 2, wherein:

said multilayer structure comprises a granular perpendicular magnetic recording layer wherein the magnetic grains are only weakly exchange coupled together, and an overlying continuous perpendicular magnetic recording layer wherein the magnetic grains are strongly exchange coupled laterally together.

4. The medium as in claim 3, wherein:

said granular perpendicular magnetic recording layer and said continuous perpendicular magnetic recording layer are ferromagnetically coupled together to form a coupled granular-continuous (CGC) structure.

5. The medium as in claim 3, wherein:

said granular perpendicular magnetic recording layer is from about 5 to about 30 nm thick and comprised of a Co-based alloy wherein segregation of magnetic grains occurs via formation of oxides, nitrides, or carbides at the boundaries between adjacent grains.

6. The medium as in claim 3, wherein:

said continuous perpendicular magnetic recording layer is from about 2 to about 15 nm thick and comprised of one or more layers of a Co-based alloy.

7. The medium as in claim 3, wherein:

said layer stack further comprises at least one interlayer between said multilayer perpendicular magnetic recording structure and said SUL.

8. The medium as in claim 7, wherein:

said at least one interlayer comprises a Ru-containing material.

9. The medium as in claim 8, wherein:

said Ru-containing material comprises RuX, where X is at least one of B and Cr.

10. A perpendicular magnetic data/information recording, storage, and retrieval system, comprising a perpendicular magnetic recording medium as in claim 1 and a single-pole magnetic transducer head including main and auxiliary poles positioned in spaced adjacency to an upper surface of said layer stack, said single-pole transducer head comprising a front shield adjacent said main pole.

11-20. -20. (canceled)

21. A perpendicular magnetic recording medium, comprising:

(a) a non-magnetic substrate having a surface; and

(b) a plurality of overlying thin film layers forming a layer stack on said substrate surface, said layer stack including a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL),

wherein said perpendicular magnetic recording medium has only one SUL, and

said SUL has a thickness of about 40 Å

to about 100 Å

,

wherein the magnetically hard perpendicular magnetic recording layer structure comprises a granular perpendicular magnetic recording layer wherein the magnetic grains are exchange coupled together, and an overlying continuous perpendicular magnetic recording layer wherein the magnetic grains are exchange coupled laterally together, and the magnetic grains in the continuous perpendicular layer are more strongly exchange coupled than the magnetic grains in the granular perpendicular magnetic recording layer.

22. The medium as in claim 21, wherein:

said granular perpendicular magnetic recording layer and said continuous perpendicular magnetic recording layer are ferromagnetically coupled together to form a coupled granular-continuous (CGC) structure.

23. The medium as in claim 21, wherein:

said granular perpendicular magnetic recording layer is from about 5 to about 30 nm thick and comprised of a Co-based alloy wherein segregation of magnetic grains occurs via formation of oxides, nitrides, or carbides at the boundaries between adjacent grains.

24. The medium as in claim 21, wherein:

said continuous perpendicular magnetic recording layer is from about 2 to about 15 nm thick and comprised of one or more layers of a Co-based alloy.

25. The medium as in claim 21, wherein:

said layer stack further comprises at least one interlayer between said multilayer perpendicular magnetic recording structure and said SUL.

26. A perpendicular magnetic recording medium, comprising:

(a) a non-magnetic substrate having a surface; and

(b) a plurality of overlying thin film layers forming a layer stack on said substrate surface, said layer stack including a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL),

wherein said perpendicular magnetic recording medium has only one SUL, and

said SUL has a thickness of about 40 Å

to about 100 Å

,

wherein said layer stack further comprises at least one Ru-containing material interlayer between said perpendicular magnetic recording layer and said SUL.

27. The medium as in claim 26, wherein:

said Ru-containing material comprises RuX, where X is at least one of B and Cr.

28. The medium as in claim 26, wherein:

the magnetically hard perpendicular magnetic recording layer structure comprises a granular perpendicular magnetic recording layer wherein the magnetic grains are exchange coupled together, and an overlying continuous perpendicular magnetic recording layer wherein the magnetic grains are exchange coupled laterally together, and the magnetic grains in the continuous perpendicular layer are more strongly exchange coupled than the magnetic grains in the granular perpendicular magnetic recording layer.

29. The medium as in claim 26, wherein:

said granular perpendicular magnetic recording layer and said continuous perpendicular magnetic recording layer are ferromagnetically coupled together to form a coupled granular-continuous (CGC) structure.

30. The medium as in claim 26, wherein:

said granular perpendicular magnetic recording layer is from about 5 to about 30 nm thick and comprised of a Co-based alloy wherein segregation of magnetic grains occurs via formation of oxides, nitrides, or carbides at the boundaries between adjacent grains.