Thermal barrier layers and seed layers for control of thermal and structural properties of HAMR media
View Patent ↗Thermal barrier layers and seed layers for control of thermal and structural properties of heat assisted magnetic recording (HAMR) media are provided. One such HAMR medium includes a substrate, a heat sink layer on the substrate, a thermal barrier layer of SrTiO 3 on the heat sink layer, an underlayer of MgO on the thermal barrier layer, and a magnetic recording layer on the underlayer. Another such HAMR medium includes a substrate, a heat sink layer on the substrate, a thermal barrier layer of an ABO3-type oxide on the heat sink layer, and a magnetic recording layer on the thermal barrier layer.
1. A medium for heat assisted magnetic recording, the medium comprising:
a substrate;
a heat sink layer on the substrate;
a thermal barrier layer directly on the heat sink layer, the thermal barrier layer comprising SrTiO 3 ;
an underlayer on the thermal barrier layer, the underlayer comprising MgO; and
a magnetic recording layer on the underlayer,
wherein the heat sink layer is configured to dissipate heat from the magnetic recording layer.
2. The medium of claim 1 , wherein the thermal barrier layer has a cubic structure with (200) texture.
3. The medium of claim 2 , wherein the heat sink layer has a cubic structure with (200) texture.
4. The medium of claim 3 , wherein a lattice mismatch between the heat sink layer and the thermal barrier layer is less than 8 percent.
5. The medium of claim 4 , wherein the heat sink layer comprises a Cr-based alloy.
6. The medium of claim 5 , wherein the heat sink layer comprises CrW and the magnetic recording layer comprises FePt with a segregant.
7. The medium of claim 2 , wherein the underlayer has a cubic structure with (200) texture.
8. The medium of claim 1 , wherein a first thickness of the thermal barrier layer is between about 3 nm and about 10 nm and a second thickness of the underlayer is between about 2 nm and about 11 nm.
9. The medium of claim 1 , wherein a first thickness of the thermal barrier layer is about 7 nm and a second thickness of the underlayer is about 3 nm.
10. The medium of claim 1 , wherein the thermal barrier layer is configured to:
facilitate a heat transfer from the magnetic recording layer to the heat sink layer; and
impede a heat transfer from the heat sink layer to the magnetic recording layer.
11. The medium of claim 1 , wherein the thermal barrier layer is deposited at a temperature greater than 450 degrees Celsius using a first radio frequency (RF) magnetron sputtering process and the underlayer is deposited at a temperature greater than 450 degrees Celsius using a second RF magnetron sputtering process.
12. The medium of claim 11 , wherein the thermal barrier layer is deposited using a static magnet.
13. A heat assisted magnetic recording system comprising:
the medium of claim 1 ;
a near-field transducer light source configured to direct light energy on to the medium; and
a magnetic transducer configured to write information to the medium.
14. A method for fabricating a medium for heat assisted magnetic recording, the method comprising:
providing a substrate;
providing a heat sink layer on the substrate;
providing a thermal barrier layer directly on the heat sink layer, the thermal barrier layer comprising SrTiO 3 ;
providing an underlayer on the thermal barrier layer, the underlayer comprising MgO; and
providing a magnetic recording layer on the underlayer,
wherein the heat sink layer is configured to dissipate heat from the magnetic recording layer.
15. The method of claim 14 , wherein providing the thermal barrier layer on the heat sink layer comprises:
depositing the thermal barrier layer on the heat sink layer at a temperature greater than 450 degrees Celsius using a first RF magnetron sputtering process.
16. The method of claim 15 , wherein providing the underlayer on the thermal barrier layer comprises:
depositing the underlayer at a temperature greater than 450 degrees Celsius using a second RF magnetron sputtering process.
17. The method of claim 16 , wherein providing the underlayer on the thermal barrier layer further comprises:
depositing the thermal barrier layer using a static magnet.
18. The method of claim 14 , wherein the thermal barrier layer, the underlayer and the heat sink layer each has a cubic structure with (200) texture.
19. The method of claim 14 , wherein a lattice mismatch between the heat sink layer and the thermal barrier layer is less than 8 percent.
20. The method of claim 19 , wherein the heat sink layer comprises a Cr-based alloy.
21. The method of claim 14 , wherein a first thickness of the thermal barrier layer is between 3 nm and 10 nm and a second thickness of the underlayer is between 2 nm and 11 nm.
22. A medium for heat assisted magnetic recording, the medium comprising:
a substrate;
a heat sink layer on the substrate;
a thermal barrier layer directly on the heat sink layer, the thermal barrier layer comprising an ABO3-type oxide; and
a magnetic recording layer on the thermal barrier layer,
wherein the heat sink layer is configured to dissipate heat from the magnetic recording layer.
23. The medium of claim 22 , wherein the thermal barrier layer has a cubic structure with (200) texture.
24. The medium of claim 23 , wherein the heat sink layer has a cubic structure with (200) texture.
25. The medium of claim 22 , wherein the magnetic recording layer comprises FePt with a segregant.
26. The medium of claim 22 , wherein a lattice mismatch between the thermal barrier layer and the magnetic recording layer is between about 3 percent and about 8 percent.
27. The medium of claim 22 , wherein the ABO3-type oxide is selected from the group consisting of BaTiO 3 , SrHfO 3 , SrZrO 3 , PbTiO 3 and BaZrO 3 .
28. The medium of claim 22 , wherein a thermal conductivity of the thermal barrier layer is less than 10 Watts per meter Kelvin.
29. The medium of claim 22 , wherein the thermal barrier layer is configured to:
facilitate a heat transfer from the magnetic recording layer to the heat sink layer; and
impede a heat transfer from the heat sink layer to the magnetic recording layer.
30. A heat assisted magnetic recording system comprising:
the medium of claim 22 ;
a near-field transducer light source configured to direct light energy on to the medium; and
a magnetic transducer configured to write information to the medium.
31. A method for fabricating a medium for heat assisted magnetic recording, the method comprising:
providing a substrate;
providing a heat sink layer on the substrate;
providing a thermal barrier layer directly on the heat sink layer, the thermal barrier layer comprising an ABO3-type oxide; and
providing a magnetic recording layer on the thermal barrier layer,
wherein the heat sink layer is configured to dissipate heat from the magnetic recording layer.
32. The method of claim 31 , wherein the thermal barrier layer and the heat sink layer each has a cubic structure with (200) texture.
33. The method of claim 31 , wherein the ABO3-type oxide is selected from the group consisting of BaTiO 3 , SrHfO 3 , SrZrO 3 , PbTiO 3 and BaZrO 3 .
34. The method of claim 31 , wherein a thermal conductivity of the thermal barrier layer is less than 10 Watts per meter Kelvin.