Perpendicular magnetic recording medium and magnetic storage apparatus
View Patent ↗A perpendicular magnetic recording medium includes a soft magnetic underlayer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer successively stacked on a nonmagnetic substrate. The soft magnetic underlayer includes a soft magnetic layer having an amorphous structure. The underlayer includes a first underlayer, and a second underlayer provided between the first underlayer and the intermediate layer. The first underlayer is made of a TiV alloy having an amorphous structure, and the second underlayer is made of an NiW alloy including at least one element selected from a group consisting of Co, Cu, Al, Cr, and Fe. The intermediate layer is made of Ru or an Ru alloy, and wherein the soft magnetic layer, the first underlayer, and the second underlayer are stacked in this order.
1. A perpendicular magnetic recording medium comprising:
a soft magnetic underlayer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer successively stacked on a nonmagnetic substrate,
wherein the soft magnetic underlayer includes a soft magnetic layer having an amorphous structure,
wherein the underlayer includes a first underlayer, and a second underlayer provided between the first underlayer and the intermediate layer,
wherein the first underlayer is made of a TiV alloy having an amorphous structure,
wherein the second underlayer is made of an NiW alloy including at least one element selected from a group consisting of Co, Cu, Cr, and Fe,
wherein the intermediate layer is made of Ru or an Ru alloy, and wherein the soft magnetic layer, the first underlayer, and the second underlayer are stacked in this order.
2. The perpendicular magnetic recording medium as claimed in claim 1 , wherein an amount of V included within the TiV alloy is in a range of 10 atomic percent to 80 atomic percent.
3. The perpendicular magnetic recording medium as claimed in claim 2 , wherein an amount of the at least one element added to the NiW alloy is in a range of 1 atomic percent to 20 atomic percent.
4. The perpendicular magnetic recording medium as claimed in claim 1 , wherein an amount of the at least one element added to the NiW alloy is in a range of 1 atomic percent to 20 atomic percent.
5. The perpendicular magnetic recording medium as claimed in claim 4 , wherein the first underlayer has a thickness in a range of 0.2 nm to 5 nm.
6. The perpendicular magnetic recording medium as claimed in claim 1 , wherein the first underlayer has a thickness in a range of 0.2 nm to 5 nm.
7. The perpendicular magnetic recording medium as claimed in claim 2 , wherein the first underlayer has a thickness in a range of 0.2 nm to 5 nm.
8. The perpendicular magnetic recording medium as claimed in claim 3 , wherein the first underlayer has a thickness in a range of 0.2 nm to 5 nm.
9. A magnetic storage apparatus comprising:
a perpendicular magnetic recording medium that includes a soft magnetic underlayer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer successively stacked on a nonmagnetic substrate, wherein
the soft magnetic underlayer includes a soft magnetic layer having an amorphous structure,
he underlayer includes a first underlayer, and a second underlayer provided between the first underlayer and the intermediate layer,
the first underlayer is made of a TiV alloy having an amorphous structure,
the second underlayer is made of an NiW alloy including at least one element selected from a group consisting of Co, Cu, Cr, and Fe,
the intermediate layer is made of Ru or an Ru alloy, and the soft magnetic layer, the first underlayer, and the second underlayer are stacked in this order; and
a magnetic head configured to read and write information with respect to the perpendicular magnetic layer of the perpendicular magnetic recording medium.
10. The magnetic storage apparatus as claimed in claim 9 , wherein an amount of V included within the TiV alloy of the first underlayer of the perpendicular magnetic recording medium is in a range of 10 atomic percent to 80 atomic percent.
11. The magnetic storage apparatus as claimed in claim 9 , wherein an amount of the at least one element added to the NiW alloy of the second underlayer of the perpendicular magnetic recording medium is in a range of 1 atomic percent to 20 atomic percent.
12. The magnetic storage apparatus as claimed in claim 9 , wherein the first underlayer of the perpendicular magnetic recording medium has a thickness in a range of 0.2 nm to 5 nm.
13. The magnetic storage apparatus as claimed in claim 9 , wherein the magnetic head is a single-pole head.
14. The perpendicular magnetic recording medium as claimed in claim 1 , wherein the second underlayer is made of the NiW alloy further including Al.
15. The magnetic storage apparatus as claimed in claim 9 , wherein the the second underlayer of the perpendicular magnetic recording medium is made of the NiW alloy further including Al.