Perpendicular magnetic recording medium
View Patent ↗The present invention provides a perpendicular magnetic recording medium 11 having a perpendicular magnetization film 22 formed on a substrate 20, wherein a high perpendicular orientation film 24 having higher perpendicular orientation than that of the perpendicular magnetization film 22 is formed over or/and under the perpendicular magnetization film 22.
1. A perpendicular magnetic recording medium consisting of:
a perpendicular magnetization film formed on a substrate, wherein at least one high perpendicular orientation film having higher perpendicular magnetic anisotropic energy than the perpendicular magnetization film is formed over or/and under the perpendicular magnetization film;
wherein the high perpendicular orientation film is made from a RCo 5 alloy having a film thickness less than 50 nm, wherein R comprises a rare earth metal selected from the group consisting of Y, Ce, Sm, La and Pr, and said RCo 5 alloy comprises a principal component of said film, and
wherein the high perpendicular orientation film and the perpendicular orientation film are in direct contact with one another.
2. A perpendicular magnetic recording medium as claimed in claim 1 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 1×10 6 .
3. A perpendicular magnetic recording medium as claimed in claim 1 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 3×10 6 .
4. A perpendicular magnetic recording medium as claimed in claim 1 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 2×10 7 .
5. A perpendicular magnetic recording medium consisting of:
a perpendicular magnetization film formed on a substrate, wherein a high perpendicular orientation film having higher perpendicular magnetic anisotropic energy than the perpendicular magnetization film is formed directly over or/and under the perpendicular magnetization film;
wherein the high perpendicular orientation film is made from a RCo 5 or a R 2 Co 17 alloy having a film thickness less than 50 nm, wherein R comprises a rare earth metal selected from the group consisting of Y, Ce, Sm, La and Pr, and said RCo 5 or R 2 Co 17 alloy comprises a principal component of said film.
6. A perpendicular magnetic recording medium as claimed in claim 5 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 1×10 6 .
7. A perpendicular magnetic recording medium as claimed in claim 5 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 3×10 6 .
8. A perpendicular magnetic recording medium as claimed in claim 5 , wherein the high perpendicular orientation film has a perpendicular magnetic anisotropic energy which is equal to or greater than 2×10 7 .