Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Susumu Soeya

Hiroyuki Hoshiya

Moriaki Fuyama

Reiko Arai

Hiromasa Takahashi

Hiroshi Fukui

Shigeru Tadokoro

Kenchi Ito

Masaaki Sano

Katsuya Mitsuoka

Fumio Sato

Toshimichi Shintani

Shinji Narishige

Takao Imagawa

Jun Hayakawa

Yoshihiro Hamakawa

Eiji Ashida

Takahiro Odaka

Junji Tominaga

Kenichi Meguro

Kouichi Nishioka

Yuko Tsuchiya

Saburo Suzuki

Masayuki Takagi

Akira Kumagai

Technology capable of improving performance of a phase-change memory is provided. A recording/reproducing film contains Sn (tin), Sb (antimony), and Te (tellurium) and also contains an element X having a bonding strength with Te stronger than a bonding strength between Sn and Te and a bonding strength between Sb and Te. Here, the recording/reproducing film has a (SnXSb)Te alloy phase, and this (SnXSb)Te alloy phase includes a self-assembled superlattice structure.

Phase-change memory and semiconductor recording/reproducing device

A phase-change device capable of realizing a multi-level record in a superlattice phase-change memory cell in which a superlattice phase-change material is used as a recording film, and thereby achieving the reduction in power consumption and the capacity increase is provided. To a phase-change memory cell composed of GeTe/SbTesuperlattice or SnTe/SbTesuperlattice, a SET pulse is once applied to form a SET state (low resistance state). Thereafter, recording pulses having respectively different voltage values between a voltage value forming the SET state and a voltage value forming a RESET state (high resistance state) are respectively applied to the superlattice phase-change memory cell twice or more. In this manner, a read resistance (SET resistance) corresponding to a recording pulse (SET pulse) and read resistances corresponding to each of the recording pulses are obtained, so that the multi-level record can be realized.

Multi-level recording in a superlattice phase change memory cell

A phase-change memory and a semiconductor recording reproducing device capable of reducing consumed power are provided. A SnTe/SbTeSL film obtained by depositing a SnTefilm and a SbTefilm layer by layer contains a SnTe/SbTesuperlattice phase formed of SnTe and SbTe, a SnSbTe alloy phase, and a Te phase. The SnTe/SbTesuperlattice phase is diluted by the SnSbTe alloy phase and the Te phase. Here, X of the SnTefilm is represented by 4 at. %&#x2266;X&#x2266;55 at. %.

Embodiments of the invention provide a thermally assisted magnetic recording medium, which can overcome resistance against thermal fluctuation at RT and write capability, obtain a drastic temperature variation in coercive force at right below the recording temperature, and be formed at low temperature. In one embodiment, the medium has a layered structure formed of a lower high-KF ferromagnetic (F) layer formed on a substrate, satisfying T&#x3c;T, an intermediate low-Kantiferromagnetic (AF) layer satisfying T&#x3c;T, and an upper ferromagnetic (F) layer for recording and reproducing, satisfying T&#x3c;T, where Tis a recording temperature, Tis a Curie point, Tis a Neel point, Tis a blocking temperature, Kis a ferromagnetic magnetocrystalline anisotropy constant, and Kis an antiferromagnetic magnetocrystalline anisotropy constant.

Thermally assisted magnetic recording media and magnetic recording and reproducing apparatus

A method for producing a recording medium provides good throughput for mass production and reduces cost. The method facilitates the control of the shape or dimensions of a pattern obtained by microfabrication, allows an accurate pattern transfer, and provides superior uniformity. A magnetic layer is formed on a substrate. A nano-particle filmis formed on a desired portion on the magnetic layer. Using the nano-particle film as a mask, the magnetic layer is cut. A micropattern with concavities and convexities is formed on the magnetic layer by removing the nano-particle film.

Method for producing recording medium, recording medium employing said method, and information recording and reproducing apparatus

No related magnetoresistive multi-layered films made from a metal magnetic film provide sufficient reproducing output power. A high-polarized layer with a thickness of 10 nm or less is formed as a Fe-rich Fe&#x2014;O layer in contact with the interface of a non-magnetic intermediate layer and the resulting layers are heat treated to form a multi-layered film of ferromagnetic Fe&#x2014;O layers, achieving a magnetoresistive element having high magnetoresistance.

Magnetoresistive element with oxide magnetic layers and metal magnetic films deposited thereon

A magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus, comprising a substrate, a pair of magnetic shield layers consisting of a lower magnetic shield layer and an upper magnetic shield layer, a magnetoresistive sensor layer, disposed between the pair of magnetic shield layers, an electrode terminal for flowing a signal current perpendicular to the plane of the magnetoresistive sensor layer, and magnetic domain control layers for controlling Barkhausen noise of the magnetoresistive sensor layer, the magnetic domain control layers being disposed in contact with opposite ends of the magnetoresistive sensor layer consist of a material having high electric resistivity and with a specific resistance not less than 10 m&#x3a9;cm.

Magnetoresistive sensor including magnetic domain control layers having high electric resistivity, magnetic head and magnetic disk apparatus

There are provided a magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus. A magnetoresistive sensor comprising a substrate, a pair of magnetic shield layers consisting of a lower magnetic shield layer and an upper magnetic shield layer, a magnetoresistive sensor layer, disposed between the pair of magnetic shield layers, an electrode terminal for flowing a signal current perpendicular to the plane of the magnetoresistive sensor layer, and magnetic domain control layers for controlling Barkhausen noise of the magnetoresistive sensor layer, wherein the magnetic domain control layers disposed in contact with opposite ends of the magnetoresistive sensor layer consist of a material having high electric resistivity and with a specific resistance not less than 10 m&#x3a9;cm so as to give the magnetoresistive sensor having excellent reproducing resolution. The sensor is used to provide a magnetic head having excellent reproducing resolution and a magnetic disk apparatus.

A magneto-resistive device has a high reproducing output and is suitable for use as a CPP-GMR device. The magneto-resistive device has a first magnetic layer, a second magnetic layer, and a non-magnetic spacer formed between the first and second magnetic layers. The first magnetic layer contains a magnetic material whose conduction electrons belong to a first energy band, and the second magnetic layer contains a magnetic material whose conduction electrons belong to a second energy band. The first and second energy bands are attributable to orbitals of the same kind, thereby increasing the ratio of change in magnetoresistance and adjusting the electric resistance.

Magneto-resistive devices

A magnetic head at high sensitivity and with enhanced output having a magnetoresistive element of high output and optimal for use in CPP-GMR, the magnetoresistive element comprising a pinned layercontaining a half-metal, a free layerformed on one main surface of the pinned layer, a spacerformed between the pinned layerand the free layer, an anti-ferromagnetic layerformed on the main surface of the pinned layer, a soft magnetic layerformed between the pinned layerand the anti-ferromagnetic layer, and a noble-metallic layerformed between the pinned layerand the soft magnetic layer.

Magnetic head, and the magnetic read-write devices, and the magnetic memory with magnetic sensors

A magnetoresistive sensor of the type of flowing a signal sensing current perpendicular to the plane to improve resolution at reproducing a signal, a magnetic head using the magnetoresistive sensor, and a magnetic disk apparatus. A magnetoresistive sensor comprising a substrate, a pair of magnetic shield layers consisting of a lower magnetic shield layer and an upper magnetic shield layer, a magnetoresistive sensor layer, disposed between the pair of magnetic shield layers, an electrode terminal for flowing a signal current perpendicular to the plane of the magnetoresistive sensor layer, and magnetic domain control layers for controlling Barkhausen noise of the magnetoresistive sensor layer, wherein the magnetic domain control layers disposed in contact with opposite ends of the magnetoresistive sensor layer consist of a material having high electric resistivity and with a specific resistance not less than 10 m&#x3a9;cm so as to give the magnetoresistive sensor having excellent reproducing resolution.

Magnetoresistive sensor including magnetic domain control layers having high electric resistivity

A magnetic reproducing head and a magnetic recording head. The magnetic reproducing head includes a GMR or TMR magnetic sensor, and a flux guide for introducing a magnetic flux into the magnetic sensor. At least a portion of the flux guide includes a material which is capable of permitting the magnetic flux to pass therethrough at a temperature not lower than a predetermined temperature Tp, but not permitting the magnetic flux to pass therethrough at a temperature lower than Tp. Light is irradiated to only a portion of the flux guide to cause the temperature of the irradiated portion to rise up to Tp or more, thereby permitting a magnetic flux to pass only through the irradiated portion, thus narrowing the track width of magnetic reproducing head when detecting recorded information from the magnetic recording medium.

Magnetic head, magnetic recording and reproducing apparatus, method for reproducing and recording magnetic recording information

A magnetic recording and reproducing head which includes a magnetic sensor, and a flux guide for introducing a magnetic flux into the magnetic sensor. At least a portion of the flux guide is constituted by a material which permits the magnetic flux to pass therethrough at a temperature of not lower than a predetermined temperature Tp, but not permit the magnetic flux to pass therethrough at a temperature of lower than Tp. Light is irradiated to only a portion of the flux guide to cause the temperature of the irradiated portion to rise up to Tp or more, thereby permitting a magnetic flux to pass only through the irradiated portion.

A magnetoresistive element includes a first antiferromagnetic film, a first magnetic film having a magnetization direction fixed by magnetic coupling with the first antiferromagnetic film, a second antiferromagnetic film, a second magnetic film having a magnetization direction fixed by magnetic coupling with the second antiferromagnetic film, a third magnetic film having a magnetization direction able to rotate in response to an applied magnetic field, a first nonmagnetic film disposed between the first magnetic film and the third magnetic film, and a second nonmagnetic film disposed between the second magnetic film and the third magnetic film. The third magnetic film is disposed between the first nonmagnetic film and the second nonmagnetic film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic film.

Magnetoresistive element

A magnetic storage/read system includes a recording medium having tracks, and a magnetic head, including a magnetoresistive element, which reads a magnetic field from the recording medium. The magnetic storage/read system satisfies a relationship of d&lE;(12.5&times;10,)/Tr where d is a height, expressed in &mgr;m, of the magnetoresistive element in a direction perpendicular to a plane of the recording medium, and Tr is a track density, expressed in tracks per inch, of the tracks of the recording medium. The magnetoresistive element may include a first antiferromagnetic film; a first magnetic film having a magnetization direction which is fixed by magnetic coupling with the first antiferromagnetic film; a second antiferromagnetic film; a second magnetic film having a magnetization direction which is fixed by magnetic coupling with the second antiferromagnetic film; a third magnetic film having a magnetization direction which is able to rotate in response to an applied magnetic field; a first nonmagnetic conductive film disposed between the first magnetic film and the third magnetic film; and a second nonmagnetic conductive film disposed between the second magnetic film and the third magnetic film; wherein the third magnetic film is disposed between the first nonmagnetic conductive film and the second nonmagnetic conductive film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic conductive film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic conductive film.

Growing community of inventors

Kodaira, Japan

Susumu Soeya