Hitachi, Ltd.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Netherlands B.v.

Masukazu Igarashi

Yo Sato

Masato Shiimoto

Keiichi Nagasaka

Tomoo Yamamoto

Katsuro Watanabe

Yuzuru Hosoe

Kazuetsu Yoshida

Masashige Sato

Nobuyuki Inaba

Fumiko Akagi

Yohji Maruyama

Susumu Okamura

Akira Ishikawa

Masato Matsubara

Ikuo Saitoh

Harukazu Miyamoto

Masaaki Futamoto

Kenji Sugiura

Yoshio Takahashi

Ichiro Tamai

Masafumi Mochizuki

Yoshihiro Shiroishi

Hideki Saga

Yoshiyuki Hirayama

Teruaki Takeuchi

Yotsuo Yahisa

Kazusuke Yamanaka

Emi Mangyo

Masato Shimoto

Hiroshi Fukuda

Kan Yasui

Akira Kato

Yoshibumi Matsuda

Kiwamu Tanahashi

Hiroshi Kajiyama

Junko Ushiyama

Yasuo Wada

Yoshiki Kato

Hisashi Nagano

Seiichi Kondo

Tetsuya Kanbe

Hiroaki Nemoto

Hideki Zaitsu

Futoshi Tomiyama

Takayuki Ichihara

Kikuo Kusukawa

Mitsuhiro Shoda

Masaru Furukawa

Junichiro Shimizu

Akira Osaki

Tsuyoshi Uda

Jun Fumioka

Tsuneo Ichiguchi

Joe Inagaki

Takao Yonekawa

Akito Sakurai

Keizou Katou

Enji Fujita

Masao Shiimoto

A magnetic oscillator for use in Microwave Assisted Magnetic Recording (MAMR). The magnetic oscillator can be a spin torque oscillator and includes a magnetic spin polarization layer, a magnetic field generation layer and a non-magnetic intermediate layer sandwiched between the magnetic spin polarization layer and the magnetic field generation layer. The non-magnetic intermediate layer is constructed of a material that provides improved performance, increased lifespan and thermal robustness. The magnetic intermediate layer is constructed of an alloy of Ag and an element X. More preferably the element X can be Sn or Zn.

Spin torque oscillator with high spin torque efficiency and reliability

Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.

Spin torque oscillator with low magnetic moment and high perpendicular magnetic anisotropy material

The present disclosure generally relates to a high-frequency oscillator for use in a recording device having a microwave-assisted magnetic recording head. The microwave-assisted magnetic recording head achieves a large assist effect by using an extended spin torque oscillator disposed between a main magnetic pole and a pole opposite the main magnetic pole. The spin torque oscillator obtains a strong high-frequency magnetic field and comprises a first non-magnetic spin scatterer, a reference layer, a first non-magnetic spin transfer layer, a first magnetic field generating layer, a second non-magnetic spin transfer layer, a second magnetic field generating layer, and a second non-magnetic spin scatterer. The spin torque oscillator has a drive current flowing though in the direction from the first magnetic field generating layer to the reference layer.

Extended spin torque oscillator

Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO and a current switching system electrically coupled to the STO. The current switching system can be used to optimize the STO frequency by changing the STO bias polarity, i.e., by changing the direction of the current flowing to the STO. As a result, the difference between the STO frequency and the magnetic media frequency is minimized, which improves recording capability of the MAMR head.

Symmetrical STO for oscillation with both polarity bias

A magnetic head, according to one embodiment, includes a magnetized high-speed rotor placed in the vicinity of a main magnetic pole, wherein the main magnetic pole generates a magnetized rotating magnetic field, wherein information is recorded by generating a high-frequency magnetic field from the magnetized high-speed rotor and switching the magnetic head between a magnetic resonance state and a magnetization state, and wherein the magnetic head has a structure such that leaking is reduced for magnetic fields applied parallel to a magnetized rotating surface of the magnetized high-speed rotor from the main magnetic pole. Additional systems and methods are also presented.

Microwave-assisted magnetic recording device and method of formation thereof

Embodiments disclosed herein generally relate to a MAMR head. The MAMR head includes an STO. The STO has a first magnetic layer, a second magnetic layer and an interlayer disposed between the first and second magnetic layers. One of the first and second magnetic layers is made of a negative polarization material while the other magnetic layer is made of a positive polarization material. As a result, the magnetizations in the first and second magnetic layers are in the same direction when in oscillation, which suppresses the partial cancellation of the magnetizations in the first and second magnetic layers and strengthens the AC magnetic field.

Negative-polarization spin-torque-oscillator

A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.

Magnetic head, magnetic recording method and apparatus for controlling magnetic head with spin torque oscillator in a disk drive

In one embodiment, a magnetic head includes a main magnetic pole positioned configured to generate a writing magnetic field when current is applied to a write coil, and a spin torque oscillator (STO) located adjacent the main magnetic pole, the STO being configured to generate a high frequency magnetic field when current is applied thereto, wherein the high frequency magnetic field is generated simultaneously to the writing magnetic field to assist in reversing magnetization of a magnetic recording medium. The STO includes: a spin polarization layer (SPL), a field generation layer (FGL) positioned adjacent the SPL, and one or more interlayers positioned between the SPL and the FGL, and a magnetization easy axis of the SPL is positioned in an in-plane direction such that the SPL has no perpendicular magnetic anisotropy.

Low Bs spin-polarizer for spin torque oscillator

In one embodiment, a spin torque oscillator (STO) includes a reference layer having a magnetization that is capable of free in-plane rotation, a field generation layer (FGL) including at least one magnetic film having an easy magnetization plane effectively in a film plane, wherein a magnetization of the FGL is capable of in-plane rotation, and a stabilizing layer (STL) positioned on a side of the FGL opposite the reference layer, the STL including a magnetic film having an easy magnetization plane effectively in a film plane, wherein a magnetization of the STL is capable of in-plane rotation, wherein a product of a saturation magnetization of the STL multiplied by a thickness of the STL is less than half a product of a magnetization of the FGL multiplied by a thickness of the FGL.

Stabilizing layer for a spin torque oscillator (STO)

To uniformly determine the positional relationship between a main magnetic pole and a spin torque oscillator while independently optimizing the main magnetic pole and the spin torque oscillator. On a trailing end surface of a main magnetic pole, a step is provided at the boundary between the main magnetic pole and a gap material disposed on both sides thereof, and a spin torque oscillator is formed on the step. The spin torque oscillator is effectively separated into two regions by utilizing the step. Further, a part of the spin torque oscillator is removed so as to disable the unwanted region, thereby realizing a self-alignment type high frequency magnetic field assisted magnetic recording head structure such that the positions of the end portions of the main magnetic pole and the spin torque oscillator are aligned.

High frequency magnetic field assisted magnetic recording head

A spin torque oscillator is provided which is adapted to high data transfer rates and which can perform assisted magnetic recording of sufficient magnitude. A spin torque oscillator is provided with a stacked spin injection layer and a high frequency magnetic field generation layer. The stacked spin injection layer has a stacked structure in which a first magnetic layer, a coupling layer, and a second magnetic layer are stacked in the order mentioned from a far side as viewed from the high frequency magnetic field generation layer. Magnetization of the first magnetic layer and magnetization of the second magnetic layer are coupled antiparallel to each other. A polarity of the magnetization of the second magnetic layer is reversed temporally earlier than a magnetic field polarity reversal of a leakage magnetic field from the main magnetic pole.

Microwave assisted magnetic recording head having spin torque oscillator, and magnetic recording apparatus

In one embodiment, a microwave-assisted magnetic recording (MAMR) head includes a main pole configured to write data to a magnetic medium using a write magnetic field, a write coil, wherein the write magnetic field is produced by the main pole upon a recording current, I, being provided to the write coil, and a spin torque oscillator (STO) positioned near the main pole, the STO being configured to provide a high-frequency assistance magnetic field to the magnetic medium upon a STO drive current, I, being provided to the STO, wherein the STO drive current, I, is ramped-up prior to the recording current, I, being provided to the write coil in order to begin a write operation for writing data to the magnetic medium. A method of operation for the MAMR head and an apparatus including the MAMR head are also described according to additional embodiments.

Microwave-assisted magnetic recording (MAMR) head employing advanced current control to establish a magnetic resonance state

To suppress a spread of not only a recording magnetic field generated from a main pole but also a high-frequency magnetic field generated from a spin torque oscillator in a microwave assisted magnetic recording head. The main pole and the spin torque oscillator are surrounded by a trailing shield layer and are also surrounded by a side/leading shield layer with an insulator sidegap layer interposed therebetween, and a high-frequency magnetic field shield layer, which absorbs a high-frequency magnetic field generated from the spin torque oscillator, is arranged in at least part of the shield layers.

Microwave assisted magnetic recording head and magnetic data storage apparatus

Provided is a magnetic recording medium achieving both of reduction in switching field distribution and reduction in switching field intensity by high-frequency magnetic field, thus enabling high-density recording. Magnetic grains of the magnetic recording medium are made up of a recording layer and a resonance layer. The resonance layer is disposed closer to a protective layerthan the recording layer, and a magnetic material of the recording layer has anisotropy field 1.2 times or more anisotropy field of a magnetic material of the resonance layer. The magnetic material of the recording layer has saturation magnetization substantially equal to saturation magnetization of the magnetic material of the resonance layer. At the entire resonance layer and a part of the recording layer, the magnetic grains are separated from surrounding magnetic grains by a nonmagnetic material, and at a part of the recording layer, the magnetic grains are coupled with surrounding magnetic grains.

Microwave assisted magnetic recording medium and information recording apparatus using the same

In one embodiment, a MAMR head includes a main magnetic pole, a STO positioned near the main magnetic pole, the STO including a first perpendicular magnetic layer positioned above the main magnetic pole, wherein the first perpendicular magnetic layer is a first spin polarization layer having an axis of magnetic anisotropy in a direction perpendicular to a film surface, a first non-magnetic transmission layer positioned above the first perpendicular magnetic layer, a magnetic layer effectively having a plane of easy magnetization in the film surface positioned above the first non-magnetic transmission layer, the magnetic layer being a FGL, a second non-magnetic transmission layer positioned above the magnetic layer, and a second perpendicular magnetic layer positioned above the second non-magnetic transmission layer, wherein the second perpendicular magnetic layer is a second spin polarization layer having magnetic anisotropy in the direction perpendicular to the film plane.

High spin-torque efficiency spin-torque oscillator (STO) with dual spin polarization layer

Growing community of inventors

Kawagoe, Japan

Masukazu Igarashi