Tdk Corporation

Yoshikazu Soeno

Akimasa Kaizu

Makoto Moriya

Kazuya Shimakawa

Tetsuya Roppongi

Tsutomu Aoyama

Takahiro Suwa

Katsumichi Tagami

Takamitsu Tsuna

Shinji Ichikawa

Isamu Sato

Mitsuru Takai

Tetsuhito Shinohara

Masashi Shiraishi

Hirokazu Takahashi

Takeshi Wada

Takuya Adachi

Eriko Ajioka

Kei Hirata

Hiroshi Ikeda

Takashi Honda

Norikazu Ota

Koichi Terunuma

Kazuhiro Hattori

Kiyoshi Noguchi

Shuichi Okawa

Takekazu Yamane

Tatsuhiro Kobayashi

Naomichi Degawa

Hironobu Matsuzawa

Hayato Koike

Satoshi Tomikawa

Zhenyao Tang

Hiroki Matsukuma

Mitsuyoshi Kawai

A base multilayer body is made by laminating a seed layer and a buffer layer in respective order. The seed layer is an alloy layer containing tantalum (Ta) and at least one type of other metal, and having an amorphous structure or a microcrystal structure. The buffer layer is an alloy layer having a [001] plane orientation hexagonal close-packed structure and containing at least one type of a group VI metal and at least one type of a group IX metal in the periodic table. With this configuration, a magnetic layer providing a desired magnetic characteristic(s) can be laminated on the thinned base multilayer body.

Multilayer element including base multilayer body, magnetic sensor and microwave assisted magnetic head

A microwave assisted magnetic head includes a main magnetic pole; a trailing shield; and a spin torque oscillator provided between the main magnetic pole and the trailing shield. The spin torque oscillator has a first end surface configuring a part of an air bearing surface, a second end surface facing the main magnetic pole, and a third end surface facing the first end surface, the first angle &#x3b8;1 made by the first end surface and the second end surface is smaller than the second angle &#x3b8;2 formed by the second end surface and the third end surface, and the second angle &#x3b8;2 is 80 to 100 degrees.

Microwave assisted magnetic recording head with spin torque oscillator corner angle relationship, head gimbal assembly, and magnetic recording device

A microwave assisted magnetic head is equipped with a main magnetic pole that generates a recording magnetic field to be applied to a magnetic recording medium from an end surface forming a portion of an air bearing surface opposed to the magnetic recording medium, a trailing shield that is disposed interposing a write gap at a trailing side of the main magnetic pole, and that forms a magnetic path with the main magnetic pole, two side shields that are disposed at both sides of the main magnetic pole in the cross track direction, respectively, and a spin torque oscillator that is disposed within the write gap. The write gap is configured to substantially linearly extend along the cross track direction when viewed from an air bearing surface side, and is positioned between trailing-side end surfaces of the main magnetic pole and the two side shields, and a leading-side end surface of the trailing shield.

Microwave assisted magnetic head, head gimbal assembly, and magnetic recording device

A magnetic head includes a microwave-generating element connected to a ground line. The ground line is made shorter by connecting the ground line to a conductive slider substrate so that the microwave-generating element is in a nearly short-circuited end condition. This allows a microwave excitation current to be efficiently supplied to the microwave-generating element, thus enabling effective microwave-assisted recording.

Magnetic head with microwave-generating element and ground line therefor

A magnetic head includes a main magnetic pole used to apply a recording signal magnetic field to a magnetic recording medium and also includes a microwave line through which a microwave alternating current is transferred. The microwave line is connected to the main magnetic pole. The entire end surface of the main magnetic pole is positioned closer to air bearing surface than a connection portion at which the microwave line and main magnetic pole are mutually connected. Therefore, microwave assisted magnetic recording is possible without deteriorating the recording signal magnetic field.

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

A magnetic recording and reproducing apparatus includes a magnetic recording medium including a recording layer in which at least two magnetic layers are layered on a non-magnetic substrate; and a magnetic head including a main magnetic pole for applying a recording magnetic field in a direction substantially perpendicular to a recording face of the magnetic recording medium and a microwave generating element that generates a microwave magnetic field. The relationship between a thickness Ts of a magnetic layer having a lowest magnetic anisotropy energy among the at least two magnetic layers composing the recording layer of the magnetic recording medium, and a thickness Tt of the recording layer is Ts/Tt&#x2266;0.2. The microwave generating element applies the microwave magnetic field having a width broader than the width of the recording magnetic field generated by the main magnetic pole of the magnetic head to the magnetic recording medium.

Magnetic recording and reproducing apparatus

A suspension is configured to support a magnetic head slider having a recording head element for recording to a magnetic recording medium and a microwave generating element that applies a high-frequency magnetic field to the magnetic recording medium when recording to the magnetic recording medium is conducted by the recording head element. The suspension includes a flexure that supports the magnetic head slider, and a microwave signal transmission line and a recording signal transmission line that are supported by the flexure. The microwave signal transmission line is connected to the microwave generating element and configured to transmit microwave signals for generating the high-frequency magnetic field, the recording signal transmission line being connected to the recording head element and configured to transmit recording signals. The flexure has a main body part, a support part for the magnetic head slider, and a pair of arm parts that links the main body part and the support part. The recording signal transmission line is supported between the main body part and the support part by a separate support part separated from the flexure, the microwave signal transmission line is supported between the main body part and the support part by at least one of the pair of arm parts, and a portion of the one of the arm parts that supports the microwave signal transmission line has a lamination structure in which an insulating layer that supports the microwave signal transmission line on one surface and a substrate whose portion opposing the other surface of the insulating layer has conductivity are laminated.

Suspension with high conductivity ground layer for microwave signal transmission line, for magnetic head slider

A magnetic recording apparatus includes a magnetic recording medium that is provided with a first magnetic layer with magneto crystalline anisotropy energy, a second magnetic layer with magneto crystalline anisotropy energy that is smaller than the magneto crystalline anisotropy energy of the first magnetic layer, and a nonmagnetic metal layer that is positioned between the first magnetic layer and the second magnetic layer and that provides coupling force between the first magnetic layer and the second magnetic layer; and a magnetic head that includes a main pole that applies a recording magnetic field in a direction perpendicular to a film surface of the magnetic recording medium to the magnetic recording medium, and an alternate current (AC) magnetic field generator that applies an AC magnetic field with a frequency of 1-40 GHz to the magnetic recording medium.

Magnetic recording apparatus

A magnetic recording device includes a magnetic disk and a magnetic head that performs magnetic recording to the magnetic disk. The magnetic head includes a main magnetic pole layer and a microwave generating element. The magnetic recording device further includes a microwave generating element driving current control circuit. The microwave generating element driving current control circuit, during the magnetic recording, applies a microwave generating element driving current at a first current level to the microwave generating element for a period that is from at the latest a polarity reversal of the recording current before a subsequent polarity reversal of the recording voltage, and thereafter applies another microwave generating element driving current at a second current level, which is smaller than the first current level, to the microwave generating element, or stops the application of the another microwave generating element driving current until the polarity reversal of the recording voltage.

Microwave-assisted magnetic recording device and method using non-constant microwave

A suspension is configured to support a magnetic head slider having a recording head element for recording to a magnetic recording medium and a microwave generating element that applies a high-frequency magnetic field to the magnetic recording medium when recording is conducted by the recording head element. The suspension has a flexure that supports the magnetic head slider, a microwave signal transmission line and a recording signal transmission line. The microwave signal transmission line is connected to the microwave generating element and configured to transmit microwave signals for generating the high-frequency magnetic field. The microwave signal transmission line and the recording signal transmission line are supported between the main body part and the support part, a portion of which has a first lamination structure where a first ground layer is conductive and a first insulating layer supports the microwave signal transmission.

Suspension with high conductivity ground layer

A microwave assisted magnetic head includes a main magnetic pole; a trailing shield, a main coil for causing the main magnetic pole to generate a perpendicular recording field, at least one secondary coil for generating an in-plane alternate-current (AC) magnetic field with a frequency in a microwave band from a magnetic recording gap between the main magnetic pole and the trailing shield, nonmagnetic films formed on magnetic recording gap facing surfaces that are defined by the main magnetic pole and the trailing shield, the main magnetic pole and the trailing shield being configured with first soft magnetic films, and second soft magnetic films formed further on the surfaces of the nonmagnetic films. The second soft magnetic films have larger anisotropy fields than the first soft magnetic films have.

Microwave assisted magnetic recording head and magnetic recording method therewith

A head gimbal assembly includes a magnetic head slider provided with a recording head element that applies a recording magnetic field to a magnetic recording medium and a suspension that supports the magnetic head slider. The magnetic head slider further includes a microwave radiation element that radiates a microwave magnetic field from a microwave excitation current that is supplied from a microwave generating circuit, and that applies the microwave magnetic field to the magnetic recording medium when the recording head element applies the recording magnetic field to the magnetic recording medium. The suspension includes a microwave transmission line that transmits the microwave excitation current, and the microwave transmission line is provided with a matching circuit to achieve impedance matching with the microwave radiation element.

Head gimbal assembly for microwave-assisted magnetic recording in impedance matching between microwave radiation element and microwave transmission line

A magnetic head that writes information to a recording medium includes a magnetic pole layer that generates a writing magnetic field to the recording medium, a microstripline that is disposed in proximity to the magnetic pole layer and to which high frequency current is applied, and a ferromagnetic thin film that is disposed on a portion of the microstripline that faces the recording medium, and that generates a high frequency alternate-current (AC) magnetic field to be applied to the recording medium, using a current magnetic field generated on the microstripline due to the high frequency current.

Magnetic head for microwave assisted magnetic recording

A microwave assisted magnetic head of the present invention includes: at least two or more auxiliary coils that are arranged in a periphery of a writing main pole; and microwave current supply means that applies microwave currents to the at least two or more auxiliary coils. The at least two or more auxiliary coils respectively include linear body parts linearly arranged on an ABS side, two of the linear body parts of the at least two or more auxiliary coils are arranged in a substantially orthogonal positional relationship, and the microwave current supply means is configured such that the microwave current supply means changes phase differences of the microwave currents applied respectively to the at least two or more auxiliary coils. Therefore, the microwave current can be easily controlled, and thus, a circularly polarized magnetic field with high magnetization inversion efficiency can be generated as an assistance magnetic field.

Microwave assisted magnetic head and magnetic disk device

A magnetic recording-reproducing apparatus includes: a magnetic recording medium in which portions corresponding to track portions serve as recording areas and in which portions between the recording areas serve as non-recording areas; and a magnetic head having a main pole and a side shield disposed on both sides of the main pole in a cross-track direction. In the magnetic recording-reproducing apparatus, following inequality (I) is satisfied:/2+&#x2003;&#x2003;(I)where Tw is a track width, Gw is a gap width, and S is a distance between the center of the main pole of the magnetic head and an edge on the main pole side of each of the side shields.

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Tokyo, Japan

Yoshikazu Soeno