MAGNETIC RECORDING MEDIA WITH SOFT MAGNETIC UNDERLAYERS

• US 20130280556A1
• Filed: 06/17/2013
• Published: 10/24/2013
• Est. Priority Date: 12/01/2006
• Status: Abandoned Application

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Tang, Li, Xu, Weilu, Zheng, Youfeng, Rou, Shanghsien, Liu, Connie Chunling, Xue, Jianhua, Lee, Li-Lien, Nolan, Thomas P.
• Application Number:
  US13/919,983
• Publication Number:
  US 20130280556A1
• Time in Patent Office: Days
• US Class Current: 428/812
• CPC Class Codes: G11B 5/1276 including at least one magnetic thin film
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/3153 including at least one magnetic thin film coupled by interfacing to the basic magnetic thin film structure
• 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
• CPC Class Codes: Y10T 428/115 Magnetic layer composition

Abstract

Provided herein, is an apparatus that includes a nonmagnetic substrate having a surface; and a plurality of overlying thin film layers forming a layer stack on the substrate surface. The layer stack includes a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL), wherein the sum of a magnetic thickness of the layer stack is a magnetic thickness of up to about 2 memu/cm̂2.

Claims

1. An apparatus comprising:

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), wherein;

the sum of a magnetic thickness of the layer stack is a magnetic thickness of up to about 2 memu/cm̂

2.

2. The apparatus of claim 1, wherein:

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

3. The apparatus of claim 2, wherein:

the 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 apparatus of claim 3, wherein:

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

5. The apparatus of claim 3, wherein:

the 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 apparatus of claim 3, wherein:

the 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 apparatus of claim 3, wherein:

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

8. The apparatus of claim 7, wherein:

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

9. The apparatus of claim 8, wherein:

the Ru-containing material comprises RuX, where X is B or Cr.

10. The apparatus of claim 1, further comprising:

a single-pole magnetic transducer head including a main and an auxiliary pole positioned in space adjacent to an upper surface of said layer stack, wherein the single-pole transducer head includes a front shield adjacent the main pole.

11. An apparatus, comprising:

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 hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL), wherein;

the sum of a magnetic thickness of the layer stack is a magnetic thickness of up to about 2 memu/cm̂

2, and

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.

12. The apparatus of claim 11, wherein:

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

13. The apparatus of claim 11, wherein:

the 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.

14. The apparatus of claim 11, wherein:

the 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.

15. The apparatus of claim 11, wherein:

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

16. A recording device, comprising:

magnetic layers including a magnetically hard perpendicular layer, wherein the layers having a magnetic thickness of up to about 2 memu/cm̂

2.

17. The recording device of claim 16, wherein:

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

18. The recording device of claim 17, wherein:

the layer stack further comprises an Ru-containing material interlayer between the magnetically hard perpendicular layer and said SUL, and wherein the Ru-containing material comprises RuX, where X is B or Cr.

19. The recording device of claim 16, wherein:

the magnetically hard perpendicular 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.

20. The recording device of claim 16, wherein:

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

21. The recording device of claim 16, wherein:

the 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.