Perpendicular magnetic recording medium
OwnerKiwamu Tanahashi, Ichiro Tamaiinventors
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention help to provide a perpendicular magnetic recording medium in which a perpendicular magnetic recording layer is formed via a soft magnetic under-layer on a disk substrate, whereby the error rate is reduced and high density recording is enabled. According to one embodiment, the disk substrate is textured so that the center line average height (Ra) is from 0.05 nm to 0.2 nm, in which the soft magnetic under-layer is amorphous and has a film thickness from 2.5 nm to 10 nm, and the magnetic field for saturation (Hs) of the perpendicular magnetic recording layer is 7 kOe or less.
Claims17
A perpendicular magnetic recording medium in which a perpendicular magnetic recording layer is formed via a soft magnetic under-layer on a disk substrate, characterized in that said disk substrate is textured along the circumferential direction, the center line average roughness (Ra) is from 0.05 nm to 0.2 nm, said soft magnetic under-layer is amorphous, and has a film thickness from 2.5 nm to 10 nm, and the magnetic field for saturation (Hs) of said perpendicular magnetic recording layer is 7 kOe or less.
A method for forming a perpendicular magnetic recording medium comprising:
- forming an adhesion layer a disk substrate;
- forming a soft magnetic under-layer on the adhesion layer,
- forming a seed layer on the soft magnetic under-layer;
- forming an intermediate layer on the seed layer;
- forming a perpendicular magnetic recording layer on the intermediate layer,
- forming a protective layer on the perpendicular magnetic recording layer, and
- forming a lubricating layer on the protective layer;
- wherein the disk substrate is textured along the circumferential direction and the center line average roughness (Ra) is from 0.05 nm to 0.2 nm,
- wherein the said soft magnetic under-layer is amorphous and has a film thickness from 2.5 nm to 10 nm,
- wherein the magnetic field for saturation (Hs) of said perpendicular magnetic recording layer is 7 kOe or less.
Dependencies are inferred from the claim text.