Kabushiki Kaisha Toshiba

Tdk Corporation

Tomomi Funayama

Hitoshi Iwasaki

Masayuki Takagishi

Kenichiro Yamada

Masahiro Takashita

Mariko Shimizu

Junichi Akiyama

Katsuhiko Koui

Kohichi Tateyama

Hiroaki Yoda

Masatoshi Yoshikawa

Susumu Hashimoto

Masashi Sahashi

Soichi Oikawa

Hiromi Fuke

Yuichi Osawa

Kazuhiro Saito

Shuichi Murakami

Tadashi Kai

Yuzo Kamiguchi

Akihiko Takeo

Yuichi Ohsawa

Tadahiko Kobayashi

Tomoko Taguchi

Yuuzo Kamiguchi

Mariko Kitazaki

Hideaki Fukuzawa

Satoshi Shirotori

Michiko Hara

Yoichiro Tanaka

Reiko Kondoh

Isao Sakai

Yuka Aoyagi

Hiromi Sakata

Norihito Fujita

Min Li

Yuchen Zhou

Kunliang Zhang

Moris Musa Dovek

Koichi Kubo

Kenichi Takano

Akio Hori

Joe Smyth

Shinobu Sugimura

Kazuto Kashiwagi

Yoichi Tokai

Shigeru Takekado

Takashi Koizumi

Takashi Tateyama, Legal Representative

According to one embodiment, a magnetic disk device includes a magnetic recording medium, a head including a recording magnetic pole, a spin torque oscillator provided near the recording magnetic pole, and a coil which excites the recording magnetic pole, a first current supply which supplies the coil with a first current corresponding to write data, a detector which detects a first signal corresponding to the write data, and outputs a second signal in accordance with the first signal, and a second power supply which varies, in accordance with the second signal, a second current supplied to the spin torque oscillator.

Magnetic disk device and high-frequency assist recording method

According to one embodiment, a method of manufacturing a magnetic recording head includes forming a microwave oscillator to cover a main pole and a side shield and also to cross at least a part of a side gap between the main pole and the side shield, and lapping the main pole, the side shield and the microwave oscillator in a height direction while monitoring an electric resistance between the main pole and the side shield.

Method of manufacturing magnetic recording head

According to one embodiment, a magnetic recording head includes an air bearing surface, a magnetic core including a main magnetic pole and a write shield arranged to face the main magnetic pole with a write gap, a coil, and a high-frequency oscillator provided between the main magnetic pole and the write shield in the write gap. The magnetic core includes an opposite surface facing a film surface of the high-frequency oscillator, a magnetic layer, and a nonmagnetic layer in which magnetic microparticles are dispersed. The nonmagnetic layer is provided outside the magnetic layer in at least a part of the opposite surface of the magnetic core.

Magnetic recording head and disk device comprising the same

A magnetic head according to an embodiment includes: a spin valve element with three terminals including a nonmagnetic base layer, a first terminal including a first magnetic layer, a second terminal including a second magnetic layer, and a third terminal including a third magnetic layer; and a slider including a first external lead terminal connecting to the first terminal, a second external lead terminal connecting to the second terminal, and a third external lead terminal connecting to the third terminal, in an operation, a first current being caused to flow from the second external lead terminal to the third terminal via the second terminal and the nonmagnetic base layer, and a second current that is lower than the first current being caused to flow to the first terminal.

Magnetic head including spin valve element with first to third terminals in which first current flows between the second terminal and the third terminal, and second current flows to the first terminal and is lower than the first current, magnetic recording and reproducing apparatus, and method of manufacturing magnetic head

A method for measuring the frequency in a spin torque oscillator having at least a magnetic oscillation layer (MOL), junction layer, and magnetic reference layer (MRL) is disclosed. In a first embodiment, a small in-plane magnetic field is applied to the STO after a DC current is applied to excite the MOL into an oscillation state. The MRL has a perpendicular magnetization that is tilted slightly to give an in-plane magnetization component to serve as a reference layer for measuring the oscillation frequency of the MOL in-plane magnetization component. An AC voltage change is produced in the DC current as a result of variable STO resistance and directly correlates to MOL oscillation frequency. Alternatively, a field having both perpendicular and in-plane components may be applied externally or by forming the STO between two magnetic poles thereby producing an in-plane magnetization reference component in the MRL.

Perpendicular spin torque oscillator FMR frequency measurement method

A magnetic head includes a plurality of reproducing elements so that the magnetic head can acquire reproduction signals from a plurality of tracks at the same time. The magnetic head includes a first reproducing element, a first magnetic film formed on a first side wall of the first reproducing element with a first side wall insulating film interposed therebetween, a second magnetic film formed on a second side wall of the first reproducing element with a second side wall insulating film interposed therebetween, a second reproducing element electrically isolated from the first reproducing element and formed on the first magnetic film, a third magnetic film formed on the first magnetic film, and a fourth magnetic film formed on the first reproducing element and electrically isolated from the second reproducing element.

Magnetic head with multiple reproducing elements each having magnetically coupled free layers, magnetic recording reproducing apparatus and magnetic head manufacturing method

A recording head of a disk device includes a main magnetic pole, a write shield which faces the main magnetic pole with a write gap interposed therebetween, a coil configured to generate a magnetic field in the main magnetic pole, and a spin torque oscillator which is arranged in the write gap. The spin torque oscillator includes an intermediate layer formed on the main magnetic pole, a field generation layer formed on the intermediate layer, a spin injection layer, and an interface magnetic layer. The field generation layer and the spin injection layer are arranged in parallel to each other in the direction which intersects with the gap length direction of the write gap, and the spin injection layer is electrically connected with the write shield.

Magnetic recording head having narrow write gap, and disk device provided with the same

According to one embodiment, a magnetic recording head includes a main pole, a write shield facing the main pole with a write gap interposed therebetween, a recording coil, and a high-frequency oscillator including an oscillation layer provided within the write gap between an end portion of the main pole and the write shield, and an intermediate layer and a spin-injection layer stacked on the oscillation layer. The oscillation layer, the intermediate layer and the spin-injection layer are stacked in a direction intersecting the gap length direction of the write gap, and at least one of the oscillation layer and the spin-injection layer is electrically connected to one of the main pole and the write shield.

Magnetic recording head and disk apparatus with the same

According to one embodiment, a magnetic recording head includes a main magnetic pole configured to apply a recording magnetic field to a recording layer of a recording medium, a spin torque oscillator adjacent to the main magnetic pole in a vicinity of a disk-facing surface confronting the recording medium, a recording coil configured to excite the main magnetic pole, a recording current control circuit configured to supply a recording current to the recording coil, a constant current supply circuit configured to supply a constant current to the spin torque oscillator, and an inverted current supply circuit configured to supply an inverted current having a polarity different from the constant current to the spin torque oscillator.

Magnetic recording head with spin torque oscillator having inverted current supply circuit

According to one embodiment, a magnetic disk apparatus includes a main magnetic pole configured to apply a recording magnetic field to a recording medium, a recording coil configured to magnetize the main magnetic pole, a spin-torque oscillator adjacent to the main magnetic pole, and configured to generate a high frequency magnetic field, a recording current control circuit configured to supply a recording current to the recording coil, a driving current control circuit configured to supply a fixed driving current to the spin-torque oscillator, and an overshoot control circuit configured to control overshoot current of the recording current in proportion to the magnitude of the driving current after the recording current has reversed.

Magnetic disk apparatus

According to one embodiment, a main pole of a recording head includes a first magnetic pole layer and a second magnetic pole layer laminated on the trailing side of the first magnetic pole layer. The first magnetic pole layer includes a tapered portion and a first tip portion. The second magnetic pole layer includes a tapered portion and a second tip portion. A width in a track direction of the second tip portion is smaller than that of the first tip portion. The high-frequency oscillator is between the second tip portion and the trailing shield and includes a width in the track direction substantially equal to the width in the track direction of the second tip portion, and a height of the first tip portion is taller than that of the second tip portion.

Recording head with high-frequency oscillator and bi-layer main pole height/width arrangement

A magnetic head assembly includes: a magnetic recording head, a head slider, a suspension and an actuator arm. The magnetic recording head includes a spin torque oscillator and a main magnetic pole. The spin torque oscillator includes, a first magnetic layer including at least one selected from the group consisting of a Fe&#x2014;Co&#x2014;Al alloy, a Fe&#x2014;Co&#x2014;Si alloy, a Fe&#x2014;Co&#x2014;Ge alloy, a Fe&#x2014;Co&#x2014;Mn alloy a Fe&#x2014;Co&#x2014;Cr alloy and a Fe&#x2014;Co&#x2014;B alloy, a second magnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The main magnetic pole is placed together with the spin torque oscillator. The magnetic recording head is mounted on the head slider. The head slider is mounted on one end of the suspension. The actuator arm is connected to other end of the suspension.

Magnetic head assembly

An example magnetic head includes a recording pole to generate a recording magnetic field, a spin torque oscillator formed in the vicinity of the recording magnetic pole and a hard bias film provided at both end portions of a bias layer and an oscillation layer of spin torque oscillator. The hard bias film is configured to apply a magnetic field to the bias layer and the oscillation layer.

Magnetic head with spin torque oscillator and magnetic recording head

A magnetic recording head includes a magnetic pole, a spin torque oscillator, a first shield and a second shield. The magnetic pole has an air-bearing surface. The spin torque oscillator is provided so that a first side of the spin torque oscillator faces the magnetic pole in a first direction parallel to the air-bearing surface. The first shield includes a granular magnetic material, and is provided so that two portions of the first shield sandwich the spin torque oscillator in a second direction which is parallel to the air-bearing surface and perpendicular to the first direction. The second shield is provided on a second side of the spin torque oscillator opposite to the first side.

Magnetic recording head and magnetic recording/reproducing apparatus using the same

An example magnetic writing head includes a main magnetic pole, a coil to generate an ampere magnetic field to magnetize the main magnetic pole to cause the magnetized main magnetic pole to generate a magnetic field, and a laminated body. The laminated body includes a first magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole and a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole.

Magnetic recording head and magnetic recording apparatus

Growing community of inventors

Tokyo, Japan

Tomomi Funayama