Method and system for providing a magnetic recording media
View Patent ↗A method and system for providing a magnetic recording medium is disclosed. The magnetic recording medium includes a plurality of regions. Each region corresponds to a bit and includes at least one grain. The grain(s) include a plurality of magnetic layers and at least one interlayer between the magnetic layers. The grain(s) have a thickness less than an exchange length of each of the magnetic layers. In addition, at least one of the magnetic layers has a coercivity different from another of the magnetic layers.
1. A magnetic recording medium comprising:
a plurality of regions, each of the plurality of regions corresponding to a bit and including at least one grain, the at least one grain including a plurality of magnetic layers and at least one interlayer between the plurality of magnetic layers; the at least one grain having a thickness less than an exchange length of each of the plurality of magnetic layers, at least one of the plurality of magnetic layers having a coercivity different from another of the plurality of magnetic layers.
2. The magnetic recording medium of claim 1 wherein the at least one grain is configured to undergo an incoherent rotation in the presence of a magnetic field when an average temperature of the at least one grain is less than two hundred degrees Celsius and more than room temperature.
3. The magnetic recording medium of claim 1 wherein the at least one interlayer includes a nonmagnetic material.
4. The magnetic recording medium of claim 1 wherein the at least one interlayer includes a magnetic material, each of the at least one interlayer having a thickness that is sufficiently small that the at least one interlayer has no net spontaneous magnetization.
5. The magnetic recording medium of claim 1 wherein the plurality of layers includes a top layer and a bottom layer, the top layer having a higher coercivity than the bottom layer.
6. The magnetic recording medium of claim 1 wherein the plurality of layers includes a top layer and a bottom layer, the bottom layer having a higher coercivity than the bottom layer.
7. The magnetic recording medium of claim 1 wherein the plurality of layers includes a top layer and a bottom layer, the top layer having a higher magnetization than the bottom layer.
8. The magnetic recording medium of claim 1 wherein the plurality of layers includes a top layer and a bottom layer, the bottom layer having a higher coercivity than the bottom layer.
9. The magnetic recording medium of claim 1 wherein the at least one interlayer includes at least one of Cr, Pt, O2, N, B, Pt, Zr, Si, Ru, Ta, a nonmagnetic oxide, and a nonmagnetic nitride.
10. The magnetic recording medium of claim 1 wherein the plurality of magnetic layers includes at least one of CoCrX1, CoX2, CoCrX3 wherein X1 is at least one of Ta, Pt, B, C, Nd, Cu, Zr, Fe, Hf, P, O2, Si, Ni, and other nonmagnetic elements, X2 is at least one of CrPt, Cu, O 2 , N, B, Pt, Zr, Si, Ru, and Ta, and X3 is at least one of C, B, Cr, Pt, O2, Cu, Nd, Ni, and Ti.
11. The magnetic recording medium of claim 1 wherein the each of the plurality of magnetic layers lies substantially parallel to a plane and has a magnetization at angle to the plane, the angle being greater than zero and not more than ninety degrees.
12. A magnetic recording medium comprising:
a plurality of regions, each of the plurality of regions corresponding to a bit and including at least one grain, the at least one grain including a plurality of magnetic layers and at least one interlayer between the plurality of magnetic layers; the at least one grain having a thickness less than an exchange length of each of the plurality of magnetic layers, at least one of the plurality of magnetic layers having a coercivity different from another of the plurality of magnetic layers, the at least one interlayer including at least one of Cr, Pt, O2, N, B, Pt, Zr, Si, Ru, Ta, a nonmagnetic oxide, and a nonmagnetic nitride, each of the plurality of magnetic layers including at least one of CoCrX1, CoX2, CoCrX3 wherein X1 is at least one of Ta, Pt, B, C, Nd, Cu, Zr, Fe, Hf, P, O2, Si, Ni, and other nonmagnetic elements, X2 is at least one of CrPt, Cu, O 2 , N, B, Pt, Zr, Si, Ru, and Ta, and X3 is at least one of C, B, Cr, Pt, O2, Cu, Nd, Ni, and Ti.
13. A method for recording to a recording medium including a plurality of regions, each of the plurality of regions corresponding to a bit and including at least one grain, the method comprising:
applying a magnetic field to the at least one grain of at least one bit, the at least one grain including a plurality of magnetic layers and at least one interlayer between the plurality of magnetic layers; the at least one grain having a thickness less than an exchange length of each of the plurality of magnetic layers, at least one of the plurality of magnetic layers having a coercivity different from another of the plurality of magnetic layers; and
raising a temperature of the recording medium to not more than two hundred degrees Celsius.
14. The method of claim 13 wherein the raising the temperature further includes raising the temperature to at least one hundred and fifty degrees Celsius.
15. The method of claim 13 wherein the plurality of layers includes a top layer and a bottom layer, the top layer having a higher coercivity than the bottom layer.
16. The method of claim 13 wherein the plurality of layers includes a top layer and a bottom layer, the bottom layer having a higher coercivity than the bottom layer.
17. The method of claim 13 wherein the plurality of layers includes a top layer and a bottom layer, the top layer having a higher magnetization than the bottom layer.
18. The method of claim 13 wherein the plurality of layers includes a top layer and a bottom layer, the bottom layer having a higher coercivity than the bottom layer.
19. The method of claim 13 wherein the at least one interlayer includes at least one of Cr, Pt, O2, N, B, Pt, Zr, Si, Ru, Ta, a nonmagnetic oxide, and a nonmagnetic nitride.
20. The method of claim 13 wherein the plurality of magnetic layers includes at least one of CoCrX1, CoX2, CoCrX3 wherein X1 is at least one of Ta, Pt, B, C, Nd, Cu, Zr, Fe, Hf, P, O2, Si, Ni, and other nonmagnetic elements, X2 is at least one of CrPt, Cu, O 2 , N, B, Pt, Zr, Si, Ru, and Ta, and X3 is at least one of C, B, Cr, Pt, O2, Cu, Nd, Ni, and Ti.
21. The method of claim 13 wherein the each of the plurality of magnetic layers lies substantially parallel to a plane and includes a magnetization, the magnetization being at an angle to the plane, the angle being greater than zero and not more than ninety degrees.