Fujitsu Corporation

Kenichi Aoshima

Hitoshi Kanai

Kenji Noma

Junichi Kane

Yoshifumi Mizoshita

Kenji Sato

Masayoshi Shinohara

Hiroaki Wakamatsu

Noboru Takada

Chie Takeda

Junichi Ito

Takahiro Imamura

Michiaki Kanamine

Mitsumasa Okada

Kenichiro Yamada

Eiji Shimizu

Hong Jongill

Junichi Hashimoto

There is disclosed a magnetoresistive film in which increase of a coupling field accompanying thickness reduction of a middle layer is inhibited. The magnetoresistive film is a multilayered film including a pinned layer having magnetization whose direction is fixed, a nonmagnetic middle layer formed on the pinned layer, and a free layer formed on the middle layer and provided with magnetization whose direction changes in accordance with an external magnetic field, the magnetoresistive film indicates a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned layer and the magnetization direction of the free layer, and a copper oxide layer of an oxide including a copper element is formed directly on the free layer, or on the free layer via an oxide layer of a material fabricated by oxidizing a material constituting the free layer.

Magnetoresistive film, magnetoresistive head, information regeneration apparatus and magnetoresistive film manufacture method

A magnetoresistance effect magnetic head includes a magnetoresistance effect element having first and second ends. An electrically insulating biasing portion is at ends of the magnetoresistance effect element to apply a longitudinal bias magnetic field to the magnetoresistance effect element and to suppress leakage current at the ends of the magnetoresistance element. The biasing portion can include an intermediate longitudinal bias application layer disposed between a first insulating antiferromagnetic layer and a second layer that can be an antiferromagnetic layer. The bias portion can also be formed as one bias application layer.

Longitudinally biased magnetoresistance effect magnetic head and magnetic reproducing apparatus

A magnetoresistive head reproduces information recorded on a recording medium with high recording density, suppressing generation of Barkhausen noise. A magnetoresistive effect element in the head is a flat multi-layer film in which a free magnetic layer is set to a lowest layer. The head also includes a non-magnetic substrate, an insulating layer contacting a center portion of a lower surface of a substrate side of the free magnetic layer, and a pair of electrode layers. The electrode layers are formed with the insulating layer in between, contacting both edge portions of the free magnetic layer. The electrodes are formed with the same surface height as the surface height of the insulating layer. A pair of magnetic wall control layers suppress movement of a magnetic wall of the free magnetic layer.

Magnetoresistive effect type of head, manufacturing method of magnetoresistive effect type of head, and information reproducing system

An object of the present invention is to provide a magnetoresistive effect type of head that is high in the magnetoresistive rate while including the laminated ferrimagnetic film. The fixed magnetic layer of the magnetoresistive effect type of head has a first fixed magnetic layer, a second fixed magnetic layer laminated at a position farther from the free magnetic layer as compared with the first fixed magnetic layer, and an opposite-parallel-coupling intermediate layer interposed between the first fixed magnetic layer and the second fixed magnetic layer, in which magnetizations of the first and second fixed magnetic layers are coupled with one another in such a manner that the magnetizations are pointed in directions which are substantially parallel and mutually opposite. The second fixed magnetic layer is formed with a material that is different from a material of said first fixed magnetic layer, and has a resistivity higher than that of said first fixed magnetic layer.

Multi-layer magnetoresistive head and information-reproducing system

A magnetoresistance effect magnetic head includes a magnetoresistance effect element having a first end and a second end. A biasing portion is provided at the first end and the second end of the magnetoresistance effect element for applying a longitudinal bias magnetic field to the magnetoresistance effect element at the first end or the second end. The biasing portion includes an intermediate layer disposed between an antiferromagnetic first layer and a second layer.

Biasing layers for a magnetoresistance effect magnetic head using perpendicular current flow

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.

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

A spin-valve magnetoresistive sensor includes a free layer of a ferromagnetic material, a pinned layer provided on the free layer and a pinning layer of an anti-ferromagnetic material provided on the pinned layer, the anti-ferromagnetic material being an ordered alloy containing manganese. The pinned layer includes a first pinned layer of a ferromagnetic material, a second pinned layer of a ferromagnetic material provided on the first pinned layer and an intermediate layer interposed between the first and second pinned layers such that the first and second pinned layers establish a super-exchange interaction in an anti-parallel manner. The second pinned layer has a magnetic moment smaller than a magnetic moment of the first pinned layer.

Spin-valve magnetoresistive sensor and magnetic head having such a spin-valve magnetoresistive sensor

A magneto-resistive head includes a stabilizing bias layer which applies a magnetization stabilizing bias field on a magneto-resistive layer of a magneto-resistive element, and a ferromagnetic underlayer which forms an underlayer with respect to the stabilizing bias layer. The ferromagnetic underlayer is made of Fe and has a film thickness in a range of 1.3 to 2.5 nm.

Magneto-resistive head and magnetic recording and reproducing apparatus

In a current perpendicular type magnetoresistive device, a current efficiently flows in a direction perpendicular to a plane of an MR element and the sensitivity of the MR element is increased. Upper and lower shielding layers form a gap therebetween so that the MR element is situated within the gap. Upper and lower gap layers are provided within the gap so that the MR element is interposed between the upper and lower gap layers. The upper gap layer is provided between the upper shielding layer and the MR element. The lower gap layer is provided between the lower shielding layer and the MR element. The lower gap layer is formed from tantalum. An under layer formed from a material having a body-centered cubic structure is interposed between the lower shielding layer and the lower gap layer.

Magnetoresistive device having a tantalum layer connected to a shielding layer via a layer of a body-centered cubic structure

A method for manufacturing a spin valve GMR head is describe in which a fixed magnetic layer of the head may maintain magnetization in a desired orientation. In one aspect of the invention, the method comprises steps of: forming a magnetic film including at least a free magnetic layer, a non-magnetic metallic layer, a fixed magnetic layer, and a magnetic domain control layer; subjecting the magnetic film to a first heat treatment under a magnetic field to enhance magnetic anisotropy of the free magnetic layer; and subjecting the magnetic film to a second heat treatment under a magnetic field and at a higher temperature than the maximum temperature applied in the processes that precede the second heat treatment, to fix the magnetization in the fixed magnetic layer. In anther aspect of the invention, the method comprises steps of: forming a magnetic film including a free magnetic layer, a non-magnetic metallic layer, a fixed magnetic layer, and a magnetic domain control layer; subjecting the magnetic film to a first heat treatment under a magnetic field to fix the magnetization in the fixed magnetic layer; subjecting the magnetic film to a second heat treatment under a magnetic field to enhance magnetic anisotropy of the free magnetic layer; and subjecting the magnetic film to a third heat treatment in the absence of an externally applied magnetic field.

Spin valve magnetoresistive head and manufacturing method therefor

A magnetoresistive head includes an underlayer composed of one of Ni and NiFe alloy and at least one additive selected from the group consisting of Cr, Nb, Rh, and Pd. An anti-ferromagnetic layer is formed on the underlayer, and a first ferromagnetic layer is formed on the anti-ferromagnetic layer. The magnetic head also includes a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the nonmagnetic layer.

Magnetoresistive head with improved underlayer

There is provided a magnetic recording/reproducing apparatus which has an improved reliability for a reproduced signal by eliminating a deformation in a reproduced signal waveform due to a residual magnetization generated in a magnetic head. The magnetic recording/reproducing apparatus has a magnetic recording medium including a magnetic film to which information is magnetically recorded and a thin-film magnetic head including a magnetic pole and a coil provided around the magnetic pole. A current supplying circuit supplies a current to the coil so that a magnetic state of the magnetic pole is stabilized. The current is supplied to the coil after a recording operation has been completed by the thin-film magnetic head. The current may demagnetize the magnetic pole of the magnetic head, or stabilize the magnetic state of the magnetic pole.

Magnetic recording/reproducing apparatus with a current supplying

A magnetoresistance effect element exhibiting superb magnetic characteristics and anticorrosion characteristic is disclosed. The magnetoresistance effect element includes an antiferromagnetic layer composed of a material made of Ir, Rh and Mn in which an Ir content percentage is 2-6% by atom and a Mn content percentage is 71-78% by atom, or a material in which the Ir content percentage is 2-12% by atom and the Mn content percentage is 78-84% by atom.

Magnetoresistance effect element, magnetoresistance effect type head and

The present invention relates to a magnetoresistive head capable of converting a change in a magnetic field generated by a magnetic recording medium into a change in electric resistivity by utilizing spin valve magnetoresistance effect to read signal information. The magnetoresistive head comprises a first magnetic layer, a second magnetic layer formed on the first magnetic layer through a first nonmagnetic metal layer and magnetized in one direction, a third magnetic layer formed on the second magnetic layer through a second nonmagnetic metal layer, and an electric current supplying layer for applying a constant current to at least the third magnetic layer, the second nonmagnetic metal layer and the second magnetic layer in one of the same direction as and the opposite direction to the direction of magnetization of the second magnetic layer.

Growing community of inventors

Kawasaki, Japan

Kenichi Aoshima