Magnetic recording medium and magnetic recording and reproducing apparatus
View Patent ↗A perpendicular magnetic recording medium of the present invention comprises a non-magnetic substrate, and at least a backing layer, an under layer, an intermediate layer and a perpendicular magnetic recording layer, which are sequentially laminated on the non-magnetic substrate, wherein the backing layer is formed of a soft magnetic film having an amorphous structure, the under layer contains a NiW alloy containing any one or both of Co and Fe, the W content of the NiW alloy is within a range from 3 to 10 atom %, the total of the Co and Fe contents of the NiW alloy is 5 atom % or more and less than 40 atom %, the saturation magnetic flux density Bs of the NiW alloy is 280 emu/cm 3 or more, the thickness of the under layer is within a range from 2 to 20 nm, and the intermediate layer contains Ru or a Ru alloy.
1. A perpendicular magnetic recording medium comprising a non-magnetic substrate, and at least a backing layer, an under layer, an intermediate layer and a perpendicular magnetic recording layer, which are sequentially laminated on the non-magnetic substrate, wherein
the backing layer is formed of a soft magnetic film having an amorphous structure,
the under layer contains a NiW alloy containing any one or both of Co and Fe,
the W content of the NiW alloy is within a range from 3 to 10 atom %,
the total of the Co and Fe contents of the NiW alloy is 20 atom % or more and less than 40 atom %,
the saturation magnetic flux density Bs of the NiW alloy is 280 emu/cm 3 or more,
the thickness of the under layer is within a range from 10 to 20 nm, the under layer directly has contact with the backing layer, and
the intermediate layer contains Ru or a Ru alloy.
2. The perpendicular magnetic recording medium according to claim 1 , wherein the soft magnetic film contains a CoFe alloy.
3. The perpendicular magnetic recording medium according to claim 2 , wherein the Fe content of the CoFe alloy is within a range from 5 to 60 atom %.
4. A magnetic recording/reproducing apparatus comprising the perpendicular magnetic recording medium according to claim 1 , and a magnetic monopole head that performs writing of information to the perpendicular magnetic recording medium.
5. A magnetic recording/reproducing apparatus comprising the perpendicular magnetic recording medium according to claim 2 , and a magnetic monopole head that performs writing of information to the perpendicular magnetic recording medium.
6. A magnetic recording/reproducing apparatus comprising the perpendicular magnetic recording medium according to claim 3 , and a magnetic monopole head that performs writing of information to the perpendicular magnetic recording medium.
7. The perpendicular magnetic recording medium according to claim 1 , wherein the under layer contains the NiW alloy containing both of Co and Fe.