Kabushiki Kaisha Toshiba

Tdk Corporation

Yuzo Kamiguchi

Hitoshi Iwasaki

Masashi Sahashi

Susumu Hashimoto

Yuichi Ohsawa

Hiromi Yuasa

Masatoshi Yoshikawa

Hiromi Fuke

Hideaki Fukuzawa

Kazuhiro Saito

Reiko Kondoh

Atsuhito Sawabe

Hiroaki Yoda

Katsuhiko Koui

Tomohiko Nagata

Shin-ichi Nakamura

Akiko Saito

Masayuki Takagishi

Tatsuya Kishi

Tomomi Funayama

Shigeru Haneda

Shiho Okuno

Takeo Sakakubo

Junichi Akiyama

Akio Hori

Taro Oike

Hiroaki Kawashima

Hideyuki Sugiyama

Tomoaki Inokuchi

Naoharu Shimomura

Yuzo Hirayama

Tadahiko Kobayashi

Koichi Terunuma

Haruyuki Morita

Naoyuki Inoue

Noriyuki Ito

Akihiko Tsutai

Katsuhiko Koi

Masahi Sahashi

According to one embodiment, a magnetic memory includes: magnetoresistive effect elements arranged on an conductive layer; and a first circuit which passes a write current through the conductive layer and applies a control voltage to the magnetoresistive effect elements, to write data including a first value and a second value into the magnetoresistive effect elements. The first circuit adjusts at least one of a write sequence of the first value and the second value, a current value of the write current, and a pulse width of the write current, on the basis of an arrangement of the first value and the second value in the data.

Magnetic memory

A magnetoresistance effect element includes a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic metal intermediate layer located between said pinned layer and said free layer. The element also includes a pair of electrodes electrically connected to the magnetoresistance effect film to supply a sense current perpendicularly to a film plane of the magnetoresistance effect film. At least one of the pinned layer and the free layer may include a thin-film insertion layer. The nonmagnetic metal intermediate layer includes a resistance adjusting layer including at least one of oxides, nitrides and fluorides, and the thin-film insertion layer includes at least one element selected from the group consisting of iron (Fe), cobalt (Co) and nickel (Ni).

Magnetoresistance effect element having resistance adjusting layer and thin-film insertion layer

A magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, a nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer, and electrodes allowing a sense current to flow in a direction substantially perpendicular to the plane of the stack including the magnetization pinned layer, the nonmagnetic intermediate layer and the magnetization free layer. At least one of the magnetization pinned layer and the magnetization free layer is substantially formed of a binary or ternary alloy represented by the formula FeCoNi(where a+b+c=100 at %, and a&#x2266;75 at %, b&#x2266;75 at %, and c&#x2266;63 at %), or formed of an alloy having a body-centered cubic crystal structure.

Magnetoresistive device, magnetoresistive head and magnetic recording-reproducing apparatus

A magnetoresistance effect element, comprising a nonmagnetic spacer layer, first and second ferromagnetic layers separated by the nonmagnetic spacer layer, the first ferromagnetic layer having a magnetization direction at an angle relative to a magnetization direction of the second ferromagnetic layer at zero applied magnetic field, the magnetization of the first ferromagnetic layer freely rotating in a magnetic field signal, a magnetoresistance effect-improving layer comprising a plurality of metal films and disposed in contact with the first ferromagnetic layer so that the first ferromagnetic layer is disposed between the nonmagnetic spacer layer and the magnetoresistance effect-improving layer, one of the plurality of metal films disposed in contact with the first ferromagnetic layer contains metal element of not solid solution with metal element of the first ferromagnetic layer and a nonmagnetic underlayer or a nonmagnetic protecting layer disposed in contact with the magnetoresistance effect-improving layer so that the magnetoresistance effect-improving layer is disposed between the first ferromagnetic layer and the nonmagnetic underlayer or the nonmagnetic protecting layer.

Magnetoresistance effect element, magnetic head, magnetic head assembly, magnetic storage system

A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle an be interrupted when the current reaches a predetermined value.

Magnetoresistance effect element, its manufacturing method, magnetic reproducing element and magnetic memory

In a spin valve type element, an interface insertion layer () of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer () or a magnetically free layer () closer to a nonmagnetic intermediate layer (). A nonmagnetic back layer () may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.

Magnetoresistance effect element, magnetic head and magnetic reproducing apparatus

It is possible to obtain sensitivity which can achieve an excellent error rate with a high recording density. There are provided a magnetization free layer which has two opposed main surfaces, one of which is set to be generally parallel to an air bearing surface; an intermediate layer which is formed on an opposite side face of the magnetization free layer from a medium to come in contact with the magnetization free layer; and a pair of magnetization pinned layers which are formed on an opposite side face of the intermediate layer from the magnetization free layer to come in contact with the intermediate layer and extend outwardly. A sense current flows from one magnetization pinned layer to the other magnetization pinned layer through the magnetization free layer.

Magneto-resistance effect element and reproducing head

A magnetoresistance effect (MR) device incorporating a spin valve film, and a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device, wherein the magnetization direction of a free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. A pinned magnetic layer includes a pair of ferromagnetic films antiferromagnetically coupled to each other via a coupling film existing therebetween. The magnetization direction of either one of the pair of ferromagnetic films constituting the pinned magnetic layer is maintained, and a nonmagnetic high-conductivity layer is disposed adjacent to a first ferromagnetic layer on the side opposite to the side on which the first ferromagnetic layer is contacted with a nonmagnetic spacer layer. With that constitution, the device has extremely high sensitivity, and the bias point in the device is well controlled.

Magnetoresistance effect element, magnetic head, and magnetic storage system using a giant magnetoresistance effect element

A magnetoresistance effect element includes a first ferromagnetic layer (), insulating layer () overlying the first ferromagnetic layer, and second ferromagnetic layer () overlying the insulating layer. The insulating layer has formed a through hole (A) having an opening width not larger than 20 nm, and the first and second ferromagnetic layers are connected to each other via the through hole.

A base film of a hard magnetic film containing Co as a structural element has a crystal metal base film such as a Cr film formed on the main surface of a substrate and a reactive base film (mixing layer) formed between the substrate and the crystal metal base film and having a reactive amorphous layer containing a structural element of the substrate and a structural element of the crystal metal base film. A hard magnetic film containing Co as a structural element is formed on the crystal metal base film. With the crystal metal base film such as the Cr film formed on an amorphous layer, a hard magnetic film with a bi-crystal structure can be obtained with high reproducibility. With the hard magnetic film, magnetic characteristics such as coercive force Hc, residual magnetization Mr, saturated magnetization Ms, and square ratio S can be improved without need to use a thick base film. The hard magnetic film containing Co as a structural element is applied to a bias magnetic field applying film of a magnetoresistance effect device and a record layer of a magnetic record medium.

Magnetoresistance effect device having a bi-crystal structure composed of main grains each having a plurality of sub-grains

A magnetoresistance effect element a stacked film including a magnetization fixed layer in which the direction of magnetization is substantially fixed to one direction, and a magnetization free layer in which the direction of magnetization varies in response to an external magnetic field, an electrode connected to a part of a principal plane of the stacked film, the magnetoresistance effect element having a resistance varying in response to a relative angle between the direction of magnetization in the magnetization fixed layer and the direction of magnetization in the magnetization free layer, a sense current detecting the variation of the resistance being applied to the film planes of the magnetization fixed layer and the magnetization free layer via the electrode in a direction substantially perpendicular to the magnetization fixed layer and the magnetization free layer. The electrode includes a pillar electrode portion substantially perpendicularly extending from the principal plane of the stacked film, and a feed portion extending substantially in parallel to the principal plane of the stacked film and the pillar electrode portion has two conductive layers in the central portion and outer peripheral portion thereof, and the sense current being caused to flow in the opposite directions to each other in the central portion and the outer peripheral portion.

Magnetoresistance effect element, magnetic head and magnetic reproducing system

Disclosed are a high-sensitivity and high-reliability magnetoresistance effect device (MR device) in which bias point designing is easy, and also a magnetic head, a magnetic head assembly and a magnetic recording/reproducing system incorporating the MR device. In the MR device incorporating a spin valve film, the magnetization direction of the free layer is at a certain angle to the magnetization direction of a second ferromagnetic layer therein when the applied magnetic field is zero. In this, the pinned magnetic layer comprises a pair of ferromagnetic films as antiferromagnetically coupled to each other via a coupling film existing therebetween. The device is provided with a means of keeping the magnetization direction of either one of the pair of ferromagnetic films constituting the pinned magnetic layer, and with a nonmagnetic high-conductivity layer as disposed adjacent to a first ferromagnetic layer on the side opposite to the side on which the first ferromagnetic layer is contacted with a nonmagnetic spacer layer. With that constitution, the device has extremely high sensitivity, and the bias point in the device is well controlled.

There is provided a magnetoresistance effect element capable of precisely defining the active region in a CPP type MR element and of effectively suppressing and eliminating the influence of a magnetic field due to current from an electrode, and a magnetic head and magnetic reproducing system using the same. The active region of the MR element is defined by the area of a portion through which a sense current flows. Moreover, the shape of the cross section of a pillar electrode or pillar non-magnetic material for defining the active region of the element is designed to extend along the flow of a magnetic flux so as to efficiently read only a signal from a track directly below the active region. When the magnetic field due to current from the pillar electrode can not be ignored, the magnetic flux from a recording medium asymmetrically enters yokes and the magnetization free layer of the MR element to some extent. In expectation of this, if the cross section of the pillar electrode is designed to be asymmetric so as to extend along the flow of the magnetic flux, the regenerative efficiency is improved.

Magnetoresistance effect element having a pillar electrode

A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle can be interrupted when the current reaches a predetermined value.

Growing community of inventors

Yokohama, Japan

Yuzo Kamiguchi