HAMR media structure having an anisotropic thermal barrier layer
View Patent ↗A heat assisted magnetic recording (HAMR) media structure is disclosed. The HAMR media structure includes a magnetic recording layer comprising an array of magnetic grains for storing information; a heat sink layer disposed below the magnetic recording layer and having a first thermal conductivity; and an anisotropic thermal barrier layer disposed between the magnetic recording layer and the heat sink layer and having a vertical thermal conductivity and an in-plane thermal conductivity, wherein the vertical thermal conductivity is substantially higher than the in-plane thermal conductivity.
1. A heat assisted magnetic recording (HAMR) media structure comprising:
a magnetic recording layer comprising an array of magnetic grains for storing information;
a heat sink layer disposed below the magnetic recording layer and having a first thermal conductivity;
an anisotropic thermal barrier layer disposed between the magnetic recording layer and the heat sink layer and having a vertical thermal conductivity and an in-plane thermal conductivity,
wherein the anisotropic thermal barrier layer consists of a single material selected from the group consisting of graphite and mica compounds and the ratio of the vertical thermal conductivity to the in-plane thermal conductivity is greater than 3; and
a nucleation layer disposed between the magnetic recording layer and the anisotropic thermal barrier layer, wherein the nucleation layer is selected from the group consisting of SiC, TiN, TiC and RuAl.
2. The HAMR media structure of claim 1 , wherein the magnetic recording layer has a thickness between about 5 and 15 nm.
3. The HAMR media structure of claim 1 , wherein the magnetic grains comprises a soft magnetic material selected from the group consisting of FePt, Mn 3 Al, FePd, CoPt, CoPd, CoPtIr, FePtIr, FePtRh, CoRhPt, FePdRh, FePtNi, CoPtNi, and FePtCu.
4. The HAMR media structure of claim 1 , wherein each of the magnetic grains is separated from an adjacent magnetic grain by a segregant.
5. The HAMR media structure of claim 4 , wherein the segregant comprises silicon oxide, tantalum oxide, magnesium oxide, silver, carbon, titanium oxide, or a combination thereof.
6. The HAMR media structure of claim 1 , wherein the nucleation layer has a thickness between about 2 and 10 nm.
7. The HAMR media structure of claim 1 , wherein the heat sink layer has a thickness between about 20 and 200 nm.
8. The HAMR media structure of claim 1 , wherein the heat sink layer comprises copper, silver, ruthenium, nickel, aluminum, tungsten, gold, or a combination thereof.
9. The HAMR media structure of claim 1 , wherein the first thermal conductivity is higher than 40 W·m −1 ·K −1 .
10. The HAMR media structure of claim 1 , wherein the anisotropic thermal barrier layer has a thickness between about 5 and 50 nm.
11. The HAMR media structure of claim 1 , wherein the ratio of the vertical thermal conductivity to the in-plane thermal conductivity is greater than 10.
12. The HAMR media structure of claim 1 , wherein the anisotropic thermal barrier layer has a thickness between about 35 and 50 nm.