Alps Electric Co., Ltd.

Yoshihiko Kakihara

Naoya Hasegawa

Kenji Honda

Kiyoshi Sato

Masamichi Saito

Daigo Aoki

Toshinori Watanabe

Toshihiro Kuriyama

Yosuke Ide

Kenichi Tanaka

A spin-valve thin-film magnetic element includes a substrate, a composite formed thereon, and electrode layers formed on both sides of the composite. The composite includes an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer, a free magnetic layer, a mean-free-path-extending layer, and an exchange bias layer. The mean-free-path-extending layer may be a back layer or a mirror reflective layer. The mean-free-path-extending layer extends the mean free path of spin-up conduction electrons in the spin-valve thin-film magnetic element. This spin-valve thin-film magnetic element meets trends toward a narrower track width.

Spin-valve thin-film magnetic element and method for making the same

The present invention provides a spin valve thin film magnetic element including a laminate in which an antiferromagnetic layer, a pinned magnetic layer provided in contact with the antiferromagnetic layer so that the magnetization direction is pinned by an exchange coupling magnetic field with the antiferromagnetic layer, a nonmagnetic conductive layer provided in contact with the pinned magnetic layer, a second free magnetic layer provided in contact with the nonmagnetic conductive layer, a nonmagnetic intermediate layer provided in contact with the second free magnetic layer, a first free magnetic layer provided in contact with the nonmagnetic intermediate layer and antiferromagnetically coupled with the second free magnetic layer to form a ferrimagnetic state together with the second free magnetic layer, and a backed layer provided in contact with the first free magnetic layer and having higher conductivity than the first free magnetic layer are laminated. The present invention also provides a magnetic head using the spin valve thin film magnetic element.

Spin valve thin film magnetic element and thin film magnetic head

A magnetoresistive-effect device includes a multilayer film, hard bias layers arranged on both sides of the multilayer film, and electrode layers respectively deposited on the hard bias layers. The electrode layers are formed, extending over the multilayer film. Under the influence of the hard bias layers arranged on both sides of the multilayer, the multilayer film, forming the magnetoresistive-effect device, has, on the end portions thereof, insensitive regions which exhibit no substantial magnetoresistive effect. The insensitive region merely increases a direct current resistance. By extending the electrode layers over the insensitive regions of the multilayer film, a sense current is effectively flown from the electrode layer into the multilayer film. With a junction area between the electrode layer and the multilayer film increased, the direct current resistance is reduced, while the reproduction characteristics of the device are thus improved.

Magnetoresistive-effect device and method for manufacturing the same

A thin-film magnetic head includes a spin-valve thin-film magnetic element, first and second insulating layers, and first and second shielding layers. The spin-valve thin-film magnetic element includes a free magnetic layer, a nonmagnetic conductive layer, a pinned magnetic layer, an antiferromagnetic layer, a pair of bias layers, and a pair of conductive layers. The pair of conductive layers is located on one side in the thickness direction of the free magnetic layer, and the pair of bias layers is located on the other side in the thickness direction of the free magnetic layer, is disposed on both sides in the track width direction of at least a portion of the second insulating layer, and is in contact with the free magnetic layer.

Thin-film magnetic head with low barkhausen noise and floating-type magnetic head therewith

A spin valve thin-film magnetic element has an improved rate of change in resistance (&Dgr;R/R) that can be used for a narrower magnetic track. The spin valve thin-film magnetic element has a laminate that include an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic conductive layer, a free magnetic layer, a back layer, specular-reflection layers and a pair of electrode layers formed at the two sides of the laminate. Preferably the specular reflection layer includes an oxide, such as &agr;-Fe O or NiO, or a half-metal Heusler alloy, such as NiMnSb or PtMnSb.

Spin valve thin-film magnetic element

A magnetoresistive element includes a multilayered film comprising a magnetic detecting layer having a magnetoresistive effect, a pair of first antiferromagnetic layers in contact with the magnetic detecting layer of the multilayered film at a predetermined gap in the track width direction, the first antiferromagnetic layers aligning the magnetization direction of the magnetic detecting layer, and a pair of conductive layers in contact with the pair of first antiferromagnetic layers, the pair of conductive layers applying a detecting current to the multilayered film. The first antiferromagnetic layers are composed of an antiferromagnetic material having higher resistivity than that of the conductive layers. The conductive layers are superimposed with the corresponding first antiferromagnetic layers and are in contact with the magnetic detecting layer in a range of the predetermined gap. The distance between the pair of conductive layers defines a track width when the multilayered film detects an external magnetic field.

Magnetoresistive element having multilayered film capable of effectively conducting a detecting current for detecting external magnetic field and method for making the same

Magnetoresistive-effect device with extended AFM layer and method for manufacturing the same

A magnetoresistive element includes an insulating layer formed between electrode layers, and the electrode layers are formed on a multilayer film so as to be in contact with the sides of the insulating layer. The thickness of the electrode layers can therefore be kept thick even at front end faces and a sensing current can flow into the multilayer film always at a constant level.

Magnetroresistive element for effective sensing current flowing into multilayer film, and process for manufacturing the same

The present invention provides a thin film magnetic head which is prevented from producing a great step in an upper shield layer and which can decrease the probability of a short circuit between the upper shield layer or lower shield layer and a spin-valve thin film magnetic element. The thin film magnetic head includes a spin-valve thin film magnetic element including a lamination of a free magnetic layer, a nonmagnetic conductive layer, a pinned magnetic layer, and an antiferromagnetic layer, a pair of conductive layers for supplying a sensing current to the free magnetic layer, and a pair of insulating bias layers for orienting the magnetization direction of the free magnetic layer; and a pair of shield layers laminated on both sides of the spin-valve thin film magnetic element in the direction of the thickness thereof. The thin film magnetic head also has a projection formed on one of the shield layers to project toward the spin-valve thin film magnetic element side so that the pair of insulating bias layers are arranged on both sides of the projection in the direction of the track width.

Thin film magnetic head providing an essentially warp-free upper shield layer and floating magnetic head using the same

Magnetoresistive-effect device with a magnetic coupling junction

In the present invention, hard bias layers are arranged in the same layer level as a free magnetic layer, and the upper surfaces of the hard bias layers are joined to the sides of a lamination at positions lower than the upper edges of the sides of the lamination above a substrate. The upper surfaces of the hard bias layers are also joined to the sides of the lamination at the same position as or positions lower than the uppermost position of the hard bias layers above the substrate. A spin-valve thin film element is provided having a decrease in an effective magnetic field applied to the free magnetic layer, and a magnetic field in the direction opposite to the magnetization direction of the free magnetic layer, permitting sufficient control of the magnetic domain of the free magnetic layer, and exhibiting excellent stability. The present invention also provides a method of manufacturing the spin-valve thin film element.

Spin-valve thin film element and method of manufacturing the same

A magnetoresistive element includes a nonmagnetic conductive layer, first and second ferromagnetic layers which are conductive and which sandwich the nonmagnetic conductive layer, an antiferromagnetic layer magnetically coupled to the first ferromagnetic layer for fixing the magnetization direction of the first ferromagnetic layer, a bias layer magnetically coupled to the second ferromagnetic layer for aligning the magnetization direction of the second ferromagnetic layer in a direction crossing to the magnetization direction of the first ferromagnetic layer, and a pair of electrode layers for applying a sensing current to the first and second ferromagnetic layers and the nonmagnetic conductive layer. The antiferromagnetic layer, the first ferromagnetic layer, the nonmagnetic conductive layer, the second ferromagnetic layer, and the bias layer are deposited in that order. The pair of electrode layers are disposed on both ends of the bias layer, and the bias layer at a position which is not covered by the pair of electrode layers is modified to form a nonmagnetic layer for determining a track width. A method of fabricating the magnetoresistive element is also disclosed.

Spin-valve type magnetoresistive element capable of preventing barkhausen noise

A spin-valve thin-film element includes a substrate, an antiferromagnetic layer formed on the substrate, a pinned magnetic layer formed on the antiferromagnetic layer, a nonmagnetic conductive layer formed on the pinned magnetic layer, a free magnetic layer formed on the nonmagnetic conductive layer, a hard biasing layer, a conductive layer for supplying a detecting current to the pinned magnetic layer, the nonmagnetic conductive layer, and the free magnetic layer, a biasing conductive layer for controlling the direction of a variable magnetization of the free magnetic layer, and a current supply unit for supplying a current to the conductive layer and the biasing conductive layer. The current applied to the biasing conductive layer forms a current magnetic field for controlling the direction of the variable magnetization of the free magnetic layer. The spin-valve thin-film element exhibits high heat resistance, high reliability, and small asymmetry.

Spin-valve thin-film element

A longitudinal bias layer and an electrode layer are formed on a non-magnetic material layer. The longitudinal bias layer and the electrode layer are partially removed by an etching technique so that a narrow gap defining the track width Tw is formed in the longitudinal bias layer and the electrode layer. Furthermore, a three-layer film consisting of, from bottom to top, a magnetoresistance effect layer, a non-magnetic layer, and a transverse bias layer, or otherwise a spin valve film consisting of a free magnetic layer, a non-magnetic layer, a fixed magnetic layer and a bias layer is formed on the above structure. The three-layer film or the spin valve film is then partially removed by an etching technique so that the three-layer film or the spin valve film remains only in the above-described narrow gap formed in the longitudinal bias layer and the electrode layer. The shape of the side walls of the three-layer film or the spin valve film is precisely determined by the side walls of the longitudinal bias layer and the electrode layer. The resultant three-layer film or the spin valve film exhibits excellent magnetic detection characteristics. Furthermore, the longitudinal bias layer has good magnetic coupling with the magnetoresistance effect layer.

Thin-film magnetic head and production method thereof

Both of decreasing the direct current resistance and flattening of the top face of the element can be simultaneously attained by forming a first lead layer under the bottom side of a laminated body as well as by reducing the film thickness of a second lead layer located at both sides of the laminated body. Excessive signals from outside of the area of the track width Tw are not picked up during regeneration operation since the width of the laminated body is adjusted to be nearly equal to the track width Tw thereby enabling to attain a good regenerative characteristic.

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Niigata-ken, Japan

Yoshihiko Kakihara