Granted Patent B1

US 10,276,201 · App. 15/050,032 · Granted Apr 30, 2019

Abstract

Claims (60)

1. A magnetic recording medium for heat assisted magnetic recording, the medium comprising:

a substrate;

a heatsink layer on the substrate;

a dual phase seed layer on the heatsink layer, wherein the dual phase seed layer comprises MgO and a segregant, wherein a concentration of the MgO is greater than or equal to 95 percent by volume in the dual phase seed layer;

a pre-seed layer comprising MgO, wherein the dual phase seed layer is directly on the pre-seed layer and the pre-seed layer is on the heatsink layer; and

a magnetic recording layer comprising FePt on the dual phase seed layer.

2. The magnetic recording medium of claim 1 , wherein a crystal phase of the MgO is different from a crystal phase of the segregant.

3. The magnetic recording medium of claim 1 :

wherein the dual phase seed layer comprises MgO grains; and

wherein the magnetic recording layer comprises FePt grains separated by a segregant, wherein the FePt grains have about a one to one correspondence with the MgO grains.

4. The magnetic recording medium of claim 1 , wherein the segregant comprises a material selected from the group consisting of C, ZrO2, BN, AN, and combinations thereof.

5. The magnetic recording medium of claim 4 , wherein the segregant comprises C in a range of about 1 percent to 50 percent by volume.

6. The magnetic recording medium of claim 4 , wherein the segregant comprises ZrO2 in an amount less than about 5 percent by volume.

7. The magnetic recording medium of claim 1 , wherein the segregant comprises a material selected from the group consisting of an amorphous material and an amorphous alloy.

8. The magnetic recording medium of claim 1 , wherein the segregant comprises a characteristic selected from the group consisting of being chemically non-reactive with MgO, being substantially immiscible with MgO, having a lower surface energy than that of MgO, and combinations thereof.

9. The magnetic recording medium of claim 1 , wherein the magnetic recording layer comprises a multi-layer magnetic recording layer comprising:

a first magnetic recording layer comprising FePtX, where X is a material selected from the group consisting of Cu, Ni, and combinations thereof;

a second magnetic recording layer on the first magnetic recording layer and having at least one material different from the materials of the first magnetic recording layer; and

a third magnetic recording layer on the second magnetic recording layer and having at least one material different from the materials of the first magnetic recording layer.

10. The magnetic recording medium of claim 1 , wherein the magnetic recording layer further comprising:

an adhesion layer between the substrate and the heatsink layer;

an amorphous underlayer between the heatsink layer and the dual phase seed layer;

a cap layer on the magnetic recording layer; and

an overcoat layer on the cap layer.

11. The magnetic recording medium of claim 10 , further comprising a thermal barrier layer between the amorphous underlayer and the heatsink layer.

12. A method for manufacturing a magnetic recording medium for heat assisted magnetic recording, the method comprising:

providing a substrate;

providing a heatsink layer on the substrate;

providing a dual phase seed layer on the heatsink layer, wherein the dual phase seed layer comprises MgO and a segregant, wherein a concentration of the MgO is greater than or equal to 95 percent by volume in the dual phase seed layer; and

providing a magnetic recording layer comprising FePt on the dual phase seed layer.

13. The method of claim 12 , wherein a crystal phase of the MgO is different from a crystal phase of the segregant.

14. The method of claim 12 :

wherein the dual phase seed layer comprises MgO grains; and

wherein the magnetic recording layer comprises FePt grains separated by a segregant, wherein the FePt grains have about a one to one correspondence with the MgO grains.

15. The method of claim 12 , wherein the segregant comprises a material selected from the group consisting of C, ZrO2, BN, AN, and combinations thereof.

16. The method of claim 15 , wherein the segregant comprises C in a range of about 1 percent to 5 percent by volume.

17. The method of claim 15 , wherein the segregant comprises ZrO2 in an amount less than about 5 percent by volume.

18. The method of claim 12 , wherein the segregant comprises a material selected from the group consisting of an amorphous material and an amorphous alloy.

19. The method of claim 12 , wherein the segregant comprises a characteristic selected from the group consisting of being chemically non-reactive with MgO, being substantially immiscible with MgO, having a lower surface energy than that of MgO, and combinations thereof.

20. The method of claim 12 , wherein providing the magnetic recording layer comprises providing a multi-layer magnetic recording layer comprising:

providing a first magnetic recording layer comprising FePtX, where X is a material selected from the group consisting of Cu, Ni, and combinations thereof;

providing a second magnetic recording layer on the first magnetic recording layer and having at least one material different from the materials of the first magnetic recording layer; and

providing a third magnetic recording layer on the second magnetic recording layer and having at least one material different from the materials of the first magnetic recording layer.

21. The method of claim 12 , further comprising:

providing an adhesion layer between the substrate and the heatsink layer;

providing an amorphous underlayer between the heatsink layer and the dual phase seed layer;

providing a cap layer on the magnetic recording layer; and

providing an overcoat layer on the cap layer.

22. The method of claim 21 , further comprising providing a thermal barrier layer between the amorphous underlayer and the heatsink layer.

23. The method of claim 12 , further comprising:

selecting a characteristic to form a preselected grain size for grains of the MgO, wherein the characteristic is selected from the group consisting of a material of the segregant, a quantity of the segregant, and combinations thereof.

24. The method of claim 12 , further comprising:

controlling a grain size of grains of the FePt in the magnetic recording layer by selecting a characteristic to form a preselected grain size for grains of the MgO, wherein the characteristic is selected from the group consisting of a material of the segregant, a quantity of the segregant, and combinations thereof.

25. A magnetic recording medium for heat assisted magnetic recording, the medium comprising:

a substrate;

a heatsink layer on the substrate;

a dual phase seed layer on the heatsink layer, wherein the dual phase seed layer comprises MgO and a segregant, wherein a concentration of the MgO is greater than 50 percent by volume in the dual phase seed layer;

a pre-seed layer comprising MgO, wherein the dual phase seed layer is directly on the pre-seed layer and the pre-seed layer is on the heatsink layer, and wherein the pre-seed layer is devoid of any segregants and comprises a preselected texture; and

a magnetic recording layer comprising FePt on the dual phase seed layer.

26. The method of claim 12 , wherein the pre-seed layer is devoid of any segregants and comprises a preselected texture.

Assignments (6)