US 6,856,494 B2Granted

Spin-valve type thin film magnetic element having bias layers and ferromagnetic layers

AssigneeAlps Electric Co., Ltd.

InventorsMasahiro Ooshima, Eiji Umetsu, Masamichi Saito, Kenichi Tanaka, Naoya Hasegawa, Yosuke Ide

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Abstract

The present invention provides a spin-valve type thin film magnetic element that is able to certainly align the magnetization direction of the free magnetic layer in one direction by improving the exchange coupling magnetic field generated between the bias layers and ferromagnetic layer, and is able to reduce the thickness of the bias layer to be smaller than the thickness of the bias layer of the conventional spin-valve type thin film magnetic element for obtaining the same magnitude of the exchange coupling magnetic layer as that in the conventional spin-valve type thin film magnetic element.

Claims16

Dependent claims

A spin-valve type thin film magnetic element comprising:

a laminate comprising an antiferromagnetic layer, a pinned magnetic layer in contact with an antiferromagnetic layer in which the magnetization direction of the pinned magnetic layer is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer, and a non-magnetic conductive layer formed between the pinned magnetic layer and a free magnetic layer;
bias layers for aligning the magnetization direction of the free magnetic layer in the direction substantially perpendicular to the magnetization direction of the pinned magnetic layer;
ferromagnetic layers formed in contact with the bias layers;
and
conductive layers for applying a sensing current to the free magnetic layer,
wherein each of the ferromagnetic layers is divided into two sub-layers separated by a first non-magnetic intermediate layer, the sub-layers being in a ferrimagnetic state in which the magnetization direction of one sub-layer is 180 degrees different from the magnetization direction of the other sub-layer, and wherein the free magnetic layer is divided into two sub-layers separated by a second non-magnetic intermediate layer, the sub-layers being in a ferrimagnetic state in which the magnetization direction of one sub-layer is 180 degrees different from the magnetization direction of the other sub-layer, and wherein the bias layers comprise at least one material selected from the group consisting of α-Fe2O3 and CoO, and
wherein the antiferromagnetic layer comprises an alloy containing at least one element selected from the group of Pt, Pd, Rh, Fe, Ru, Ir, Os, Au, Ag, Cr, Ni, Ne, Ar, Xe and Kr, and Mn.

4 more elements

A spin-valve type thin film magnetic element comprising:

a laminate comprising an antiferromagnetic layer, a pinned magnetic layer in contact with an antiferromagnetic layer in which the magnetization direction of the pinned magnetic layer is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer, and a non-magnetic conductive layer formed between the pinned magnetic layer and a free magnetic layer;
bias layers for aligning the magnetization direction of the free magnetic layer in the direction substantially perpendicular to the magnetization direction of the pinned magnetic layer;
ferromagnetic layers formed in contact with the bias layers;
and
conductive layers for applying a sensing current to the free magnetic layer,
wherein each of the ferromagnetic layers is divided into two sub-layers separated by a first non-magnetic intermediate layer, the sub-layers being in a ferrimagnetic state in which the magnetization direction of one sub-layer is 180 degrees different from the magnetization direction of the other sub-layer, and
wherein the free magnetic layer comprises a first free magnetic layer and a second free magnetic layer which are separated by the second non-magnetic intermediate layer, the first free magnetic layer and the second free magnetic layer are in a ferrimagnetic state in which the magnetization direction of the first free magnetic layer is 180 degrees different from the magnetization direction of the second free magnetic layer, the first free magnetic layer is disposed between the non-magnetic conductive layer and the second non-magnetic intermediate layer, the first free magnetic layer comprises a laminate of a CoFe alloy film and a CoFeNi alloy film, and the CoFe alloy film is formed at the non-magnetic conductive layer side, and the second non-magnetic intermediate layer comprises Ru.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/885,871Filed 20 Jun 2001 · continuation in part
Priority: JP 2000-08528724 Mar 2000
Published: US 2002/0024781 A128 Feb 2002
Granted: 15 Feb 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G11B 5/3903
Using magneto-resistive devices or effects: using magnetic thin film layers or their effects, the films being part of integrated structures
B82Y 10/00
Nanotechnology for information processing, storage or transmission
B82Y 25/00
Nanomagnetism
H01F 10/3272
The exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e.…:…