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Magnetic disk apparatus

A technology of a magnetic disk device and a magnetic head, which is applied in the directions of information recording, magnetic recording, and magnetic recording layer on the magnetic disk, and can solve the problems that the recording density and external field resistance cannot be satisfied at the same time.

Inactive Publication Date: 2006-09-13
KK TOSHIBA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, if the external field resistance is increased under the condition of reducing the track width of the unipolar head to about 150nm in order to increase the recording density, it is required that the magnetic permeability of the soft undercoat should be reduced to 50 or less
Therefore, the technology disclosed in Japanese Patent Application Laid-Open No. 2000-90424 cannot meet the requirements of recording density and external field resistance at the same time.

Method used

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  • Magnetic disk apparatus
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no. 1 example

[0021] figure 1 A cross-sectional view of the magnetic disk device according to the present embodiment is shown. The magnetic disk device includes a magnetic recording medium (perpendicular dual-layer medium) 10 and a magnetic head 50 . The magnetic recording medium 10 has a structure in which a soft undercoat layer 13 (including a soft magnetic layer 14a, a nonmagnetic layer 15, and a soft magnetic layer 14b), an intermediate nonmagnetic layer 16, and a perpendicular recording layer are stacked on a nonmagnetic substrate 11. 17. The magnetic head 50 is a so-called monopole head and includes a main pole 51 , a side yoke 52 and an exciting coil 53 .

[0022] The soft magnetic layers 14 a , 14 b in the soft undercoat layer 13 are antiferromagnetically coupled via the nonmagnetic layer 15 . Examples of materials for the soft magnetic layers 14a, 14b include soft magnetic materials with high magnetic permeability, such as CoZrNb alloys, FeTaC alloys, FeZrN alloys, FeSi alloys, ...

no. 2 example

[0035] In order to increase the recording density of a magnetic disk device, it is inevitable to increase the track density. Therefore, it is considered that the road width should be continuously reduced. However, as the track width decreases, the strength of the magnetic field at the end of the unipolar head weakens, which may result in a decrease in the overwrite performance (OW). According to this embodiment, a medium that can improve external field resistance without reducing the effective thickness B·t of the soft undercoat layer while keeping the overwrite performance (OW) unchanged will be introduced next.

[0036]FIG. 6 shows a sectional view of the magnetic disk device according to the present embodiment. The magnetic disk device is composed of a magnetic recording medium (perpendicular double-layer medium) 20 and a magnetic head 50 . In the magnetic recording medium 20, a soft undercoat layer 22, an intermediate nonmagnetic layer 23, and a perpendicular recording l...

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Abstract

A magnetic disk apparatus includes a magnetic recording media having a substrate, a data recording layer formed on one surface of the substrate and including a magnetic recording layer, and a shield layer formed on the other surface of the substrate and including a soft magnetic layer and no magnetic recording layer, and a magnetic head.

Description

technical field [0001] The present invention relates to a magnetic disk device. Background technique [0002] For magnetic disk devices, it is necessary to reduce the influence of external fields. In particular, perpendicular magnetic disk devices are susceptible to external fields. The reason for this is as follows. A perpendicular magnetic disk device includes a vertical double-layer medium including a soft undercoat layer and a vertical The recording layer, the magnetic head includes a main pole, a side yoke and an excitation coil. Since the soft undercoat layer included in the vertical double-layer medium has strong sensitivity to the magnetic field on its entire surface, the magnetic information recorded in the medium is easily changed by an external field. For example, if an external field changes the magnetic coupling between the head and the soft undercoat, it will change the read output. If a high external field is applied, the magnetic head may change the magne...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G11B5/667G11B5/73G11B5/012
CPCG11B5/667G11B5/11G11B2005/0029
Inventor 青柳由果
Owner KK TOSHIBA