US 7,402,348 B2 · Perpendicular magnetic recording medium

Abstract

A magnetic recording layer is formed on an auxiliary magnetic layer in a perpendicular magnetic recording medium. The auxiliary magnetic layer has the axis of easy magnetization in the vertical direction perpendicular to the surface of a substrate. The perpendicular magnetic recording medium reliably allows establishment of the magnetization in the auxiliary magnetic layer in the vertical direction. When a magnetic flux flows along the vertical direction perpendicular to the surface of the magnetic recording layer, the magnetic flux flows across the magnetic recording layer in the vertical direction. The magnetization is thus reliably established in the magnetic recording layer in the vertical direction. The magnetic field of a stronger intensity is thus leaked out of the magnetic recording layer in the vertical direction.

Claims9

Dependent claims

A perpendicular magnetic recording medium comprising:

a substrate;
a magnetic recording layer having an axis of easy magnetization in a vertical direction perpendicular to a surface of the substrate;
and
an auxiliary magnetic layer receiving the magnetic recording layer, said auxiliary magnetic layer having an axis of easy magnetization in the vertical direction,
wherein a product of a thickness and a residual magnetic flux density for said auxiliary magnetic layer is set equal to or smaller than one fifth a product of a thickness and a residual magnetic flux density for the magnetic recording layer.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

11/088,241Filed 23 Mar 2005 · continuation

Priority

17 Oct 2002

Published

US 2005/0249982 A110 Nov 2005

Granted

22 Jul 2008

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

G11B 5/676
The record carriers consisting of several layers: having magnetic layers separated by a nonmagnetic layer, e.g. antiferromagnetic layer, Cu layer…
G11B 5/012
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor: recording on, or…
G11B 2005/0029
Pulse recording: using magnetisation components of the recording layer disposed mainly perpendicularly to the record carrier surface
Y10T 428/24975
Absolute thicknesses specified: no layer or component greater than 5 mils thick

Perpendicular magnetic recording medium

Life of this patent

Perpendicular magnetic recording medium

Life of this patent

Abstract

Claims9