Kabushiki Kaisha Toshiba

Kohichi Tateyama

Hiroaki Yoda

Tomomi Funayama

Michiko Hara

Masayuki Takagishi

Masatoshi Yoshikawa

Yuichi Ohsawa

Tadahiko Kobayashi

Akio Hori

Hiromi Sakata

Hitoshi Iwasaki

Tomohiko Nagata

Susumu Hashimoto

Junichi Akiyama

Reiko Kondoh

Toshihiko Ohta

Takashi Koizumi

Takeo Sakakubo

Katsutaro Ichihara

Hideaki Fukuzawa

Akira Kikitsu

Katsuhiko Koui

Ryo Sakai

Takashi Ishigami

Naoyuki Inoue

Yoichiro Tanaka

Atsuhito Sawabe

Shigeru Takekado

Yusuke Ohinata

Tomomi Tunayama

Takasi Koizumi

Kei Sakoda

Disclosed is a CCP-CPP-GMR head assembly which has: a CCP-CPP-GMR head that includes at least a current control layer having as a microstructure a plurality of truncated cone electric conductors with axes the same as a current direction and an insulator filling between the plurality of truncated cone electric conductors, and in which a surface on which a larger-area basal plane of the plurality of truncated cone electric conductors is greater in number is a first surface of the current control layer and a surface of an opposite side of the first surface is a second surface of the current control layer; and a sense current source providing the CCP-CPP-GMR head with a sense current that flows from the second surface to the first surface, a magnetic recording/reproducing apparatus having such a head, and a specification method of an appropriate sense current direction of the CCP-CPP-GMR head.

CCP-CPP-GMR head assembly, magnetic recording/reproducing apparatus, and specification method of appropriate sense current direction of CCP-CPP-GMR head

A magnetoresistance effect element of the dual spin valve type using a current-perpendicular-to-the-plane (CPP) system where a sensing current flows perpendicular to the stacked faces of a plurality of conductive layers, the magnetoresistance effect element comprises a first unit which includes a free layer and a first pinning layer, a second unit which includes the free layer shared with the first unit and a second pinning layer, a first current control layer which is provided in the first unit and limits the flow quantity of the sensing current, and a second current control layer which is provided in the second unit and limits the flow quantity of the sensing current.

Current-perpendicular-to-plane magnetoresistance effect device with double current control layers

CCP-CCP-GMR head assembly with good operating life, and magnetic recording/reproducing apparatus therewith

A magnetoresistive element includes a magnetoresistive film having a magnetization pinned layer, a magnetization free layer, and a nonmagnetic intermediate layer. A magnetization direction of the magnetization pinned layer is substantially fixed in an external magnetic field, a magnetization direction of the magnetization free layer is configured to change in the external magnetic field, and the nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer and has a stacked structure of a first non-metallic intermediate layer/a metal intermediate layer/a second non-metallic intermediate layer. The magnetoresistive element also includes a pair of electrodes coupled to the magnetoresistive film and is configured to provide a current in a direction substantially perpendicular to a surface of the magnetoresistive film.

Magnetoresistive element, magnetoresistive head and magnetic reproducing apparatus

A magnetic recording head, a magnetic reproducing head, a magnetic recording apparatus comprising the magnetic recording head, and a magnetic reproducing apparatus comprising the magnetic reproducing head are described. The magnetic reproducing head having a magnetic gap at a medium-facing surface and includes a pair of magnetic yokes of ferromagnetic material, a magnetoresistance effect film, and a pair of biasing films. One of the pair of magnetic yokes has a magnetic tip at the medium-facing surface and also a rear portion recessed from the medium-facing surface and magnetically coupled to the magnetic tip. The magnetic tip has a first width in a track width direction at the medium-facing surface, and the rear portion has a second width in the track width direction wider than the first width. The magnetoresistance effect film is recessed from the medium-facing surface and is magnetically coupled to the pair of magnetic yokes of ferromagnetic material. The pair of biasing films are recessed from the medium-facing surface and one of the pair of biasing films comprises a hard magnetic material layer disposed adjacent to the rear portion or an antiferromagnetic material layer disposed in contact with the rear portion. The magnetic tip may be provided with appropriate volume of the magnetic biasing from the magnetic biasing film and magnetic domains in the magnetic tip may be sufficiently controlled.

Magnetic recording head, a magnetic reproducing head, a magnetic recording apparatus, and a magnetic reproducing apparatus

In a magnetic head having magnetic yoke layers, each magnetic yoke layer includes a yoke projecting portion (A) projected toward a recording medium, and yoke setback portions (B) set back from the yoke projecting portion. A first bias magnetic field applying film () of an antiferromagnetic material is formed to cover the yoke projecting portion whereas a second bias magnetic field applying film () of a ferromagnetic material may be formed on opposite side surfaces of the yoke projecting portion.

Magnetic head and magnetic reproducing apparatus

A magnetic head is configured by forming a thin-film-shaped magnetic element on top of a thin film that is provided parallel to a medium-facing surface. An aperture is formed in the thin film, and part of a main magnetic pole is formed to have a tip portion that protrudes into that aperture. This configuration makes it possible to impose highly accurate control over the amount by which thin-film-shaped magnetic elements are recessed from the medium-facing surface, while simultaneously exerting accurate control over the amount of protrusion of the main magnetic pole tip portion by making the thickness of the thin film extremely small. As a result, the recording flux strength at the main magnetic pole tip portion can be increased to the ultimate value thereof, making it possible to supply a head that can record on a high retention force medium suitable for higher densities.

Method a fabricating a magnetic head

In a yoke type reproducing magnetic head, a magnetoresistance effect film can be arranged in the vicinity of a medium facing surface, so that sensitivity is improved. The yoke type reproducing magnetic head comprises: a pair of magnetic yokes which face each other via a magnetic gap, at least one of the pair of magnetic yokes extending from a medium facing surface to a position retracted from the medium facing surface; a magnetoresistance effect film which has a curved portion protruding toward the medium facing surface in the magnetic gap and which is magnetically connected to the magnetic yokes; and an electrode which is electrically connected to the magnetoresistance effect film.

Magnetic head including a magneto resistive film connected to a yoke portion

In a magnetoresistive effect element, at least one of electrodes for supplying a current perpendicularly to the film plane of a magnetoresistive effect film is narrower than the distance between bias-applying films. The sensitivity of the magnetoresistive effect film is lower in regions thereof near the bias-applying films due to an intensive bias magnetic field from the bias-applying films. However, the electrodes are disposed in an inner region having a high sensitivity avoiding those regions with a lower sensitivity to ensure a high sensitivity. The electrodes disposed on and under the magnetoresistive effect film are pillar-shaped to concentrate the sense current such that the sense current can be concentrically supplied exclusively to the region with the high sensitivity.

Magnetoresistive effect element, its manufacturing method, magnetic head, magnetic reproducing apparatus, and magnetic memory

A method for manufacturing a magnetic head which includes a lower write pole having a projection, an upper write pole having a projection opposed to the projection of the lower write pole, and a magnetic gap interposed between the projection of the upper write pole and the projection of the lower write pole, comprising: a first step of making the magnetic gap on the projection of the lower write pole; a second step of making a non-magnetic material layer on the lower write pole, the non-magnetic material layer having a projection on its top surface in positional alignment with the projection of the lower write pole; a third step of making a mask layer on the non-magnetic material layer, the mask layer having an opening in which the top surface of the projection of the non-magnetic material layer is exposed; a fourth step of making a curved recess in the non-magnetic material layer by isotropically etching the non-magnetic material layer through the opening of the mask layer; a fifth step of making an approximately tapered recess down from the bottom of the curved recess by anisotropically etching the non-magnetic material layer through the opening of the mask layer; and a sixth step of making the upper write pole by burying a magnetic material in the tapered recess and the curved recess is provided.

Magnetic head manufacturing method

A current perpendicular to plane type magnetoresistive device has a magnetoresistive film, a pair of electrodes which allow a sense current to flow through the magnetoresistive film in a perpendicular direction to the plane thereof, and a biasing film which imparts a biasing magnetic field to the magnetoresistive film in a parallel direction to film plane. The direction of the magnetic field generated by the sense current flowing through the magnetoresistive film in the perpendicular direction to film plane is made substantially anti-parallel to the direction of the biasing magnetic field in a vicinity of a portion of the magnetoresistive film where a signal magnetic flux is introduced.

Current perpendicular to plane type magnetoresistive device, magnetic head, and magnetic recording/reproducing apparatus

A method for manufacturing a magnetic head which includes a lower write pole having a projection, an upper write pole having a projection opposed to the projection of the lower write pole, and a magnetic gap interposed between the projection of the upper write pole and the projection of the upper write pole, comprising: a first step of making the magnetic gap on the projection of the lower write pole; a second step of making a non-magnetic material layer on the lower write pole, the non-magnetic material layer having a projection on its top surface in positional alignment with the projection of the lower write pole; a third step of making a mask layer on the non-magnetic material layer, the mask layer having an opening in which the top surface of the projection of the non-magnetic material layer is exposed; a fourth step of making a curved recess in the non-magnetic material layer by isotropically etching the non-magnetic material layer through the opening of the mask layer; a fifth step of making an approximately tapered recess down from the bottom of the curved recess by anisotropically etching the non-magnetic material layer through the opening of the mask layer; and a sixth step of making the upper write pole by burying a magnetic material in the tapered recess and the curved recess is provided.

There is provided a magnetic recording apparatus capable of carrying out signal reproduction with high accuracy by using a narrow gap head structure corresponding to high recording density. An asymmetric gap structure MR head includes a magnetoresistance element,having a magnetoresistance film,and a pair of electrodes,disposed at the upper side; a reproducing magnetic gap film,disposed only at the lower side of the magnetoresistance element,; a magnetic shielding film,disposed so as to make a laminate with the magnetoresistance element,through the reproducing magnetic gap film,; and an insulating film,disposed at the upper side of the magnetoresistance element,. When a signal is read by use of such a reproducing head, the signal of the present bit is read by subtracting a value obtained by multiplying signals of a plurality of previous bits by predetermined coefficients from the present reproduction signal. As another reproduction signal processing system, a partial response system is adopted.

Magnetic recording apparatus

At least one magnetic pole out of a pair of magnetic poles is provided with a T-shaped magnetic pole having a magnetic pole chip at the position contacting with a magnetic gap and an auxiliary magnetic pole which is wider than thereof. The proximity of an air bearing surface of the T-shaped magnetic pole is composed of a laminated film containing a magnetic material layer with a high saturated magnetic flux density which composes the magnetic pole chip and a portion of the auxiliary magnetic pole and a magnetic material layer with a low saturated magnetic flux density which composes the remaining portion of the auxiliary magnetic pole. When the front portion of the magnetic pole with the track width of 1.8 &mgr;m or less is composed of a laminated film containing a magnetic material layer having a high saturated magnetic flux density and a magnetic material layer having a low saturated magnetic flux density, the thickness of the magnetic material layer having the high saturated magnetic flux density is 0.5 &mgr;m or more. According to the above described magnetic pole, the magnetic saturation near the tip portion of the magnetic pole is controlled, so that preferable magnetic field strength and magnetic field gradient can be attained when the track width is narrowed.

Magnetic head

A thin-film magnetic head comprises a magnetic gap disposed to be positioned on an air bearing surface of the magnetic head, a pair of magnetic poles disposed to hold the magnetic gap therebetween, and a coil positioned between the pair of the magnetic poles to intersect the magnetic poles, wherein at least one of the magnetic poles being composed of a T-shaped magnetic pole, the T-shaped magnetic pole comprising a front part of a magnetic pole contacting with the magnetic gap, an intermediate part of a magnetic pole lying on the front part, and a rear part of a magnetic pole lying on the intermediate part, wherein a width of the front part roughly defines a track width, the rear part has a wider width in a direction of track width than a width of the front part, and the intermediate part contacts with the rear part at an entire width of the rear part at the air bearing surface and has a narrower width at a contacting face with the front part than the width of the rear part.

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Yokohama, Japan

Kohichi Tateyama