Magnetic recording medium with guard layer between auxiliary and magnetic recording layers and manufacturing method of the magnetic recording medium
View Patent ↗It is an object to manufacture magnetic recording media with the high recording density. Since nonmagnetic portions ( 8 ) with a predetermined pattern are formed in a recording auxiliary layer ( 4 ) formed on a magnetic recording layer ( 3 ), it is possible to actualize a magnetic recording medium where magnetic portions ( 7 ) and the magnetic recording layer ( 3 ) immediately below the portions ( 7 ) are recording units. The nonmagnetic portions ( 8 ) are formed by non-magnetization using ion implantation, and it is thereby possible to manufacture magnetic recording media with the high recording density.
1. A magnetic recording medium comprising:
a nonmagnetic substrate;
a magnetic recording layer that is a perpendicular magnetic film in which an axis of easy magnetization is oriented substantially perpendicularly to a substrate surface of the nonmagnetic substrate; and
a recording auxiliary layer having magnetism that is directly formed on the magnetic recording layer,
wherein the recording auxiliary layer has magnetic portions having magnetism and nonmagnetic portions made nonmagnetic by including implanted ions, the magnetic portions exist in areas corresponding to track regions, and the nonmagnetic portions exist in areas corresponding to between track regions,
wherein a guard layer is formed between the magnetic recording layer and the recording auxiliary layer, serving to block migration of implanted ions into the recording layer,
wherein the guard layer has a thickness sufficiently thin that it precludes formation of crystals, and
wherein the guard layer is made of a material having at least one of Ru, Pt or CoCrSiO2 as a main component.
2. The magnetic recording medium according to claim 1 , wherein a film thickness of the recording auxiliary layer is thinner than a film thickness of the magnetic recording layer, whereby non-magnetic particles can be formed in a desired pattern.
3. The magnetic recording medium according to claim 1 , wherein a protective layer is formed on the recording auxiliary layer, and a distance from the top surface of the protective layer to the top surface of the recording auxiliary layer is 7 nm or less.
4. The magnetic recording medium according to claim 1 , wherein the magnetic portions in the recording auxiliary layer are perpendicular magnetic films where the axis of easy magnetization is oriented substantially perpendicularly to the nonmagnetic substrate.