Two dimensional amorphous carbon as overcoat for heat assisted magnetic recording media
A recording device comprising an overcoat layer, wherein the overcoat layer comprises an amorphous carbon overcoat layer having a crystallinity (C)≤0.8.
1. A recording device comprising:
an overcoat layer on a substrate,
wherein the overcoat layer comprises an amorphous carbon layer having a crystallinity (C) ≤0.8,
wherein the crystallinity (C)=number of hexagons:(number of hexagons+number of non-hexagons).
2. The device of claim 1 , wherein the overcoat layer comprises a two-dimensional (2D) amorphous carbon film.
3. The device of claim 2 , wherein the 2D amorphous carbon film has a resistivity of 0.01 to 1000 Ω-cm, inclusive.
4. The device of claim 2 , wherein the 2D amorphous carbon film has a crystallinity (C)≤0.8 and a sp 3 /sp 2 bond ratio is 0.2 or less.
5. The device of claim 2 , wherein the 2D amorphous carbon film has a transparency equal to or greater than 98% at a wavelength of 550 nm or higher.
6. The device of claim 2 , wherein a water contact angle of the overcoat layer is 60.
7. The device of claim 2 , wherein the 2D amorphous carbon film contains an Sp2 carbon bond of more than 99%.
8. The device of claim 2 , wherein the 2D amorphous carbon film undergoes substantially no bond change up to 700° C.
9. The device of claim 2 , wherein a range of coefficient of friction (COF) of the 2D amorphous carbon film is approximately 0.2-0.4.
10. The device of claim 2 , wherein the 2D amorphous carbon film has a reflection less than 5% in an ultraviolet (UV) region.
11. The device of claim 1 , wherein the recording device comprises a magnetic recording media.
12. The device of claim 1 , wherein the recording device is a heat assisted magnetic recording media.
13. The device of claim 1 , comprising:
an underlying magnetic recording layer,
wherein the overcoat layer protects the underlying magnetic recording layer.
14. The device of claim 1 , comprising additional layers.
15. The device of claim 14 , wherein the additional layers are selected from the group consisting of:
a substrate layer;
an adhesion layer;
a heat sink layer;
a soft under layer;
another under layer;
a recording layer;
a capping layer; a lubricant layer; and combinations thereof.
16. The device of claim 15 , wherein the substrate layer is selected from the group consisting of: metallic substrates, glass, and an oxide of a material.
17. A magnetic recording media device comprising:
a substrate layer;
an adhesion layer;
a heat sink layer;
a soft under layer;
another under layer;
a recording layer;
a capping layer;
an overcoat layer; and
a lubricant layer,
wherein the overcoat layer comprises an amorphous carbon overcoat layer having a crystallinity (C)≤0.8, and
wherein the crystallinity (C)=number of hexagons:(number of hexagons+number of non-hexagons).
18. The device of claim 17 , wherein the overcoat layer comprises a two-dimensional (2D) amorphous carbon film.
19. The device of claim 18 , wherein the 2D amorphous carbon film contains an Sp2 carbon bond of more than 99%.
20. The device of claim 18 , wherein the 2D amorphous carbon film undergoes substantially no bond change up to 700° C.
21. The device of claim 18 , wherein a range of coefficient of friction (COF) of the 2D amorphous carbon film is approximately 0.2-0.4.
22. The device of claim 18 , wherein the 2D amorphous carbon film has a reflection less than 5% in an ultraviolet (UV) region.