Dual segregant heat assisted magnetic recording (HAMR) media

Patent metadata

Field	Value
Publication number	US-9324353-B2
Application number	US-201314084535-A
Country	US
Kind code	B2
Filing date	Nov 19, 2013
Priority date	Nov 19, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

In one embodiment, a magnetic media suitable for HAMR recording includes a recording layer having first and second magnetic layers. The first magnetic layer has a first segregant between magnetic grains thereof, the first segregant being primarily C. Moreover, the second magnetic layer is formed above the first magnetic layer. The second magnetic layer has a second segregant between magnetic grains thereof, the second segregant being primarily C and a second component. Additional systems and methods are also described herein.

First claim

What is claimed is:

1. A magnetic medium, comprising:
a recording layer having first and second magnetic layers,
the first magnetic layer having a first segregant between magnetic grains thereof, the first segregant being primarily C,
the second magnetic layer being formed above the first magnetic layer, the second magnetic layer having a second segregant between magnetic grains thereof, the second segregant being primarily C and a second component,
wherein an average pitch of the magnetic grains in the first magnetic layer and the second magnetic layer is in a range from about 2 nm to about 11 nm.

2. The magnetic medium as recited in claim 1 , wherein the second component is selected from a group consisting of: SiO 2 , TiO 2 , TaO x , SiC, SiN, TiC, TiN, BN, BC, Cr 2 O 3 , CrN.

3. The magnetic medium as recited in claim 2 , wherein the second component is BN.

4. The magnetic medium as recited in claim 2 , wherein the recording layer has a third magnetic layer having a third segregant between magnetic grains thereof, the third segregant comprising C and a third component, the third component of the third segregant being different than the second component of the second segregant.

5. The magnetic medium as recited in claim 4 , wherein a C content in the third segregant is less than a C content in the second segregant.

6. The magnetic medium as recited in claim, wherein a C content in the second segregant is in a range of about 50 to about 80 vol %, wherein a content of the second component in the second segregant is in a range of about 20 to about 50 vol %.

7. The magnetic medium as recited in claim 6 , wherein the second component is selected from a group consisting of: SiO 2 , TiO 2 , TaO x , SiC, SiN, TiC, TiN, BN, BC, Cr 2 O 3 , CrN.

8. The magnetic medium as recited in claim 1 , wherein the magnetic grains of the second magnetic layer are physically characterized by growth directly on the magnetic grains of the first magnetic layer.

9. The magnetic medium as recited in claim 1 , wherein the magnetic grains of the first and second magnetic layers form composite magnetic grains extending through the recording layer, wherein a total thickness of the composite magnetic grains is at least 6 nm, and wherein the composite magnetic grains have an average aspect ratio of at least 1.2.

10. The magnetic medium as recited in claim 1 , wherein the first and second magnetic layers each comprise FePt.

11. The magnetic medium as recited in claim 1 , wherein the magnetic grains of at least one of the first and second magnetic layers each comprise FePt—X, where is X is selected from a group consisting of Ag, Cu, Au, Ni, and Mn.

12. A magnetic data storage system, comprising:
at least one magnetic head;
a magnetic medium as recited in claim 1 ;
a drive mechanism for passing the magnetic medium over the at least ne magnetic head; and
a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

13. The magnetic medium as recited in claim 1 , comprising a first underlayer formed below and on the first magnetic layer, wherein the first underlayer comprises FePt.

14. The magnetic medium as recited in claim 13 , comprising: a second underlayer formed below and on the first underlayer, the second underlayer comprising MgO and SiO 2 ; and a third underlayer formed below and on the second underlayer, the third underlayer comprising MgO.

15. A magnetic medium, comprising:
a recording layer having first and second magnetic layers each comprising FePt,
the first magnetic layer having a first segregant between magnetic grains thereof,
the second magnetic layer being formed above the first magnetic layer, the second magnetic layer having a second segregant between magnetic grains thereof, the second segregant being different than the first segregant,
wherein an average pitch of the magnetic grains in the first magnetic layer and the second magnetic layer is in a range from 2 nm to 11 nm.

16. The magnetic medium as recited in claim 15 , wherein the first magnetic layer includes about 20 to about 50 vol % of C, the C being almost entirely in the first segregant of the first magnetic layer.

17. The magnetic medium as recited in claim 15 , wherein a C content in the second segregant is in a range of about 50 to about 80 vol %, and wherein a content of a second component in the second segregant is in a range of about 20 to about 50 vol %.

18. The magnetic medium as recited in claim 17 , wherein the second component is selected from a group consisting of: SiO 2 , TiO 2 , TaO x , SiC, SiN, TiC, TiN, BN, BC, Cr 2 O 3 , CrN.

19. The magnetic medium as recited in claim 17 , wherein the second component is BN.

20. The magnetic medium as recited in claim 15 , wherein magnetic grains of the second magnetic layer are physically characterized by growth directly on magnetic grains of the first magnetic layer.

21. The magnetic medium as recited in claim 15 , wherein the magnetic grains of the first and second magnetic layers form composite magnetic grains extending through the recording layer, wherein a total thickness of the composite magnetic grains is at least 6 nm.

22. A magnetic data storage system, comprising:
at least one magnetic head;
a magnetic medium as recited in claim 15 ;
a drive mechanism for passing the magnetic medium over the at least one magnetic head; and
a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

23. The magnetic medium as recited in claim 15 , wherein the magnetic grains of the first and second magnetic layers each comprise FePt—X, where is X is Ni and/or Mn.

Assignees

• HGST Netherlands BV

Inventors

• Hellwig Olav
• Mosendz Oleksandr
• Pisana Simone
• Weller Dieter K

Classifications

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/66 Primary

  the record carriers consisting of several layers · CPC title

• G11B5/65

  characterised by its composition (G11B5/66 takes precedence) · CPC title

• G11B5/672 Primary

  having different compositions in a plurality of magnetic layers, e.g. layer compositions having differing elemental components or differing proportions of elements · CPC title

• G11B5/674

  having differing macroscopic or microscopic structures, e.g. differing crystalline lattices, varying atomic structures or differing roughnesses · CPC title