Magnetic recording medium and method of manufacturing the same, and magnetic record/reproduction apparatus
View Patent ↗According to the present invention, a magnetic recording medium is provided including a disk-shaped non-magnetic substrate and at least a perpendicular magnetic layer formed on the disk-shaped non-magnetic substrate, wherein the perpendicular magnetic layer has a structure in which an FePt or CoPt nanoparticle array is formed on a formation surface, on which a plurality of striations each having a circumferential directional component are formed, by a texturing treatment; a manufacturing method thereof; and a magnetic record/reproduction apparatus including the magnetic recording medium or a magnetic recording medium manufactured according to the manufacturing method.
1. A method of manufacturing a magnetic recording medium comprising a disk-shaped non-magnetic substrate and at least a perpendicular magnetic layer formed on the disk-shaped non-magnetic substrate, the method comprising the steps of:
applying a texturing treatment to a formation surface, on which the perpendicular magnetic layer is formed, to form a plurality of striations each having a circumferential directional component on the formation surface, said texturing treatment is performed by pressing a texturing tape onto the surface of the non-magnetic substrate while dripping a polishing solution;
bringing a dispersion of FePt or CoPt nanoparticles dispersed by a dispersant into contact with an entire surface of the formation surface subjected to the texturing treatment to form an FePt or CoPt nanoparticle array that serves as the perpendicular magnetic layer on the formation surface, wherein a surface roughness of the non-magnetic substrate subjected to the texturing treatment is set to fall within a range of 0.15 to 1 nm in center line average roughness (Ra) and a distance between the adjacent striations is set to fall within a range of 10 to 20 nm, and
sequentially stacking a soft magnetic underlayer and an intermediate layer that serves as the formation surface between the non-magnetic subtrate and the perpendicular magnetic layer
wherein said texturing treatment is applied to a surface of the intermediate layer after a sputtering treatment.
2. The method of manufacturing a magnetic recording medium according to claim 1 , wherein the texturing treatment is applied to a surface of the non-magnetic substrate that serves as the formation surface.
3. The method of manufacturing a magnetic recording medium according to claim 1 , wherein an average particle diameter of the FePt or CoPt nanoparticles falls within a range of 3 to 5 nm.
4. A magnetic record/reproduction apparatus comprising:
the magnetic recording medium according to claim 1 ;
a medium driving unit that drives the magnetic recording medium in a recording direction;
a magnetic head that performs a recording operation and a reproduction operation relative to the magnetic recording medium;
head moving means configured to move the magnetic head relative to the magnetic recording medium; and
a recording/reproduction signal processing means configured to input a signal to the magnetic head and reproduce an output signal from the magnetic head.
5. A magnetic record/reproduction apparatus comprising:
the magnetic recording medium manufactured by the manufacturing method according claim 1 ;
a medium driving unit that drives the magnetic recording medium in a recording direction;
a magnetic head that performs a recording operation and a reproduction operation relative to the magnetic recording medium;
head moving means configured to move the magnetic head relative to the magnetic recording medium; and
a recording/reproduction signal processing means configured to input a signal to the magnetic head and reproduce an output signal from the magnetic head.
6. The method of manufacturing a magnetic recording medium according to claim 1 , wherein the polishing solution contains diamond abrasive particles or alumina abrasive particles.