Perpendicular magnetic recording media with laminated soft magnetic underlayer
AssigneeSeagate Technology LLC
InventorsDmitri Litvinov, Sakhrat Khizroev, James Kent Howard, Roy Wallace Gustafson
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Abstract
Magnetic recording media having a biased soft magnetic underlayer are disclosed. The soft magnetic underlayer includes at least two soft magnetic layers separated by a thin non-magnetic layer. Magnetostatic coupling between the soft magnetic layers causes the magnetizations in the layer to be anti-parallel. The biased soft magnetic underlayer is brought into a substantially single-domain state, thereby reducing or eliminating unwanted noise in the soft underlayer. In a preferred embodiment, the recording media includes a perpendicular magnetic recording disk.
Claims20
A perpendicular magnetic recording medium comprising:
- a hard magnetic recording layer;
- and
- a soft magnetic underlayer under the hard magnetic recording layer, wherein the soft magnetic underlayer comprises means for generating a noise-reducing reducing magnetic field in the soft magnetic underlayer.
A laminated soft magnetic underlayer of a perpendicular magnetic recording medium, the laminated soft magnetic underlayer comprising first and second layers of magnetically soft material separated by a non-magnetic spacer layer which generate a noise-reducing magnetic field in the soft magnetic underlayer.
A method of making a laminated magnetically soft underlayer of a perpendicular magnetic recording disk, the method comprising:
- depositing a first magnetically soft layer on a substrate disk;
- depositing a non-magnetic layer on the first magnetically soft layer;
- depositing a second magnetically soft layer on the non-magnetic layer;
- and
- generating a noise-reducing magnetic field in the soft magnetic underlayer.
Dependencies are inferred from the claim text.