Patterned magnetic recording medium having reduced magnetic interaction between neighboring magnetic recording layers
View Patent ↗A patterned magnetic recording medium including a plurality of magnetic recording domains arranged at predetermined regular intervals on a substrate, wherein the magnetic recording domains are multi-layered and comprise a soft magnetic layer interposed between a first ferromagnetic layer and a second ferromagnetic layer. The soft magnetic layer suppresses magnetic interaction between a respective one of the magnetic recording domains and neighboring ones of the magnetic recording domains.
1. A patterned magnetic recording medium comprising:
a plurality of patterned magnetic recording domains arranged at regular intervals on a substrate,
wherein each of the magnetic recording domains is a multi-layer laminate which is disposed vertically with respect to the substrate,
wherein each respective one of the magnetic recording domains comprises:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a soft magnetic layer interposed between the first ferromagnetic layer and the second ferromagnetic layer;
a first non-magnetic layer disposed between the first ferromagnetic layer and the soft magnetic layer; and
a second non-magnetic layer disposed between the second ferromagnetic layer and the soft magnetic layer;
wherein the soft magnetic layer suppresses magnetic interaction between the respective one of the magnetic recording domains and neighboring ones of the magnetic recording domains relative to magnetic interaction that would occur if the soft magnetic layer were not disposed in the respective one of the magnetic recording domains.
2. The patterned magnetic recording medium of claim 1 , wherein the magnetic anisotropic energy of each one of the first and second ferromagnetic layers is 10 6 -10 7 erg/cm 3 .
3. The patterned magnetic recording medium of claim 1 , wherein the thickness of each one of the first and second ferromagnetic layers is 2-10 nm.
4. The patterned magnetic recording medium of claim 1 , wherein the first and second ferromagnetic layers are each one of a CoCrPt layer, a CoPtP layer, a multi-layer comprising a Co layer and a Pt layer, and another multi-layer comprising a Fe layer and a Pt layer.
5. The patterned magnetic recording medium of claim 1 , wherein the magnetic anisotropic energy of the soft magnetic layer is 50-10000 erg/cm 3 .
6. The patterned magnetic recording medium of claim 1 , wherein the thickness of soft magnetic layer is 2-10 nm.
7. The patterned magnetic recording medium of claim 1 , wherein the soft magnetic layer is one of a CoFe layer, a NiFe layer, a CoNiFe layer, and a Co layer.
8. The patterned magnetic recording medium of claim 1 , wherein 4 πMs is 0.3-1.5 Tesla, where Ms is the saturation magnetization of the soft magnetic layer.
9. The patterned magnetic recording medium of claim 1 , wherein the thickness of each one of the first and second non-magnetic layers is 1-5 nm.
10. The patterned magnetic recording medium of claim 1 , wherein each one of the first and second non-magnetic layers is one of a Cu layer, a Pt layer, a Ru layer, a Ta layer, a NiFeCr layer, and a Cr layer.
11. The patterned magnetic recording medium of claim 1 , wherein a maximum switching magnetic distribution of the patterned magnetic recording medium is less than 70%.
12. The patterned magnetic recording medium of claim 1 , wherein a maximum switching magnetic distribution of the patterned magnetic recording medium is less than 38%.
13. The patterned magnetic recording medium of claim 1 , wherein a maximum switching magnetic distribution of the patterned magnetic recording medium is less than 20%.
14. The patterned magnetic recording medium of claim 1 , wherein 4 πMs is 0.3-0.7 Tesla, where Ms is the saturation magnetization of the soft magnetic layer.