Spin-valve magnetoresistive head, and composite-type magnetic head and magnetic recording medium drive using the same

• US 20020034057A1
• Filed: 11/26/2001
• Published: 03/21/2002
• Est. Priority Date: 07/05/1999
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kanai, Hitoshi, Kane, Junichi, Noma, Kenji, Aoshima, Kenichi
• Granted Patent: US 6,501,627 B2
• Time in Patent Office: Days
• US Class Current: 360/324.12
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence

Abstract

A spin-valve magnetoresistive head having end parts of a free magnetic layer insensitive to an external magnetic field so as to improve sensitivity is provided.

The spin-valve magnetoresistive head includes, at least on the terminal part sides, a lamination formed of a first antiferromagnetic layer, a soft magnetic layer, an antiparallel coupling intermediate layer, and a first free magnetic layer.

Claims

1. A spin-valve magnetoresistive head having a device part and terminal parts provided to both ends of the device part, the spin-valve magnetoresistive head comprising:

a first free magnetic layer formed from one to the other of the terminal parts; and

a lamination in the terminal parts on said first free magnetic layer, the lamination including an antiparallel coupling intermediate layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.

2. The spin-valve magnetoresistive head as claimed in claim 1, wherein:

the antiparallel coupling intermediate layer is formed from the one to the other of the terminal parts through the device part; and

a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described under said first free magnetic layer from a side thereof.

3. The spin-valve magnetoresistive head as claimed in claim 1, wherein:

the antiparallel coupling intermediate layer and the soft magnetic layer are formed from the one to the other of the terminal parts through the device part;

the soft magnetic layer serves as a second free magnetic layer; and

a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described under said first free magnetic layer from a side thereof.

4. The spin-valve magnetoresistive head as claimed in claim 1, wherein:

the antiparallel coupling intermediate layer and the soft magnetic layer are formed from the one to the other of the terminal parts;

the soft magnetic layer serves as a second free magnetic layer; and

a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described on the second free magnetic layer from a side thereof in the device part.

5. The spin-valve magnetoresistive head as claimed in claim 1, wherein a nonmagnetic layer, a pinned magnetic layer, and a second antiferromagnetic layer are provided in an order described on said first free magnetic layer from a side thereof in the device part.

6. The spin-valve magnetoresistive head as claimed in any of claims 1 to 5, wherein the first antiferromagnetic layer has an exchange coupling magnetic field of 100 to 400 Oe with the soft magnetic layer or the second free magnetic layer.

7. The spin-valve magnetoresistive head as claimed in any of claims 1 to 5, wherein the antiparallel coupling intermediate layer includes ruthenium.

8. A composite-type magnetic head having a magnetic head for reproduction and a magnetic head for recording, wherein:

the magnetic head for reproduction is a spin-valve magnetoresistive head comprising a device part, terminal parts provided to both ends of the device part, and a lamination including a first free magnetic layer formed from one to the other of the terminal parts, an antiparallel coupling intermediate layer in the terminal parts on the first free magnetic layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.

9. A magnetic recording medium drive including a magnetic recording medium and a composite-type magnetic head for recording and reproduction, the composite-type magnetic head opposing a surface of the magnetic recording medium, the magnetic recording medium drive comprising:

a spin-valve magnetoresistive head as a reproducing magnetic head part of the composite-type magnetic head, the spin-valve magnetoresistive head including a device part, terminal parts provided to both ends of the device part, and a lamination including a first free magnetic layer formed from one to the other of the terminal parts, an antiparallel coupling intermediate layer in the terminal parts on the first free magnetic layer, a soft magnetic layer, and a first antiferromagnetic layer, the antiparallel coupling intermediate layer having a function of making front and rear magnetization orientation of a magnetic layer contacting the antiparallel coupling intermediate layer substantially antiparallel, the first antiferromagnetic layer applying to the soft magnetic layer a bias magnetic field substantially perpendicular to a direction of an external magnetic field to be detected.