Hitachi, Ltd.

Western Digital Technologies, Inc.

Hitachi Global Storage Technologies Japan, Ltd.

Tokyo Institute of Technology

Hitachi Global Storage Technologies

Hisashi Takano

Quang Le

Xiaoyong Liu

Kazuo Shiiki

Cherngye Hwang

Yasutaka Nishida

Isamu Yuito

Hideo Tanabe

Naoki Koyama

Eijin Moriwaki

Takehiko Hamaguchi

Mikio Suzuki

Kuok San Ho

Brian Rodrick York

Toshio Kobayashi

Hideki Sawaguchi

Kyo Akagi

Yoshibumi Matsuda

Fumio Kugiya

Masaaki Futamoto

Masahiro Kitada

Yoshinori Miyamura

Takeshi Nakao

Futoshi Tomiyama

Yohji Maruyama

Ryoichi Nakatani

Hirotsugu Fukuoka

Takayuki Munemoto

Tokuho Takagaki

Noboru Shimizu

Hideo Todokoro

Moriaki Fuyama

Tohru Ishitani

Tsuyoshi Ohnishi

Chiaki Ishikawa

Toru Matsushita

Son T Le

Takashi Kawabe

Hongquan Jiang

Nam Hai Pham

Zhanjie Li

Tomohiro Okada

Hiroshi Ide

Hideki Zaitsu

Masaaki Sano

Kenzo Masuda

Shun-ichi Narumi

Hiroshi Ikekame

Yoshiaki Kita

Hisano Yamamoto

Zhigang Bai

Michael Gribelyuk

Hassan Osman

Fan Tuo

Atsushi Nakamura

Masafumi Mochizuki

Hiroyuki Tsuchinaga

Yoshihiro Hamakawa

Hiroshi Fukui

Yoshio Suzuki

Matahiro Komuro

Susumu Okamura

Tetsuo Ito

Takayuki Ichihara

Yoji Maruyama

Reijiro Tsuchiya

Makoto Aihara

Maki Maeda

Miki Hara

Rohan Babu Nagabhirava

Masafumi Michizuki

Huy H Ho

Yoshimi Kawanami

Hiroyuki Shinada

Kaoru Umemura

Satoshi Tomimatsu

Norio Ohta

Noriyuki Kumasaka

Yoshihiro Shiroishi

Hitoshi Nakamura

Nobuyuki Inaba

Qing Dai

Kenji Mori

Yoshiaki Kawato

Hiroshi Suzuki

Shigekazu Otomo

Toshiaki Tsuyoshi

Hajime Aoi

Yuichi Madokoro

Yasuhide Ouchi

Yosuke Seo

Shinobu Sasaki

Xiaoyu Xu

Tan Duy Trinh

Andrew Chen

Alan Spool

Yasuo Wakaki

Takeshi Nakano

Khang H D Nguyen

The present disclosure generally relates to temperature detection devices including a ferromagnetic (FM) material disposed at a media facing surface (MFS). The FM material is configured to produce a first electric voltage signal in response to a temperature gradient due to an anomalous Nernst effect. The temperature detection device may also include a spin-orbit torque (SOT) material abutting the FM material. The SOT material includes at least one of BiSb, a topological insulator, a topological half-Heusler alloy, or a weakly oxidized heavy metal. The SOT material is recessed from the MFS, wherein the SOT material is configured to receive a spin current parallel to the temperature gradient generated by a spin Seebeck effect in the FM material. The spin current is detectable as a second electric voltage signal via an inverse spin Hall effect. The first electric voltage signal is added to the second electric voltage signal.

Spin orbit torque based thermal sensor for insitu monitoring of magnetic recording head

Nitrogen doping an insulating layer can lower the bandgap of a magnetic storage device. It is challenging to nitrogen dope magnesium oxide (MgO). A cation can be added to allow the magnesium to hold onto the nitrogen dopant without highly oxidizing or nitriding the cation. The resulting nitrogen doped MgXO, where X is the cation, has a lower bandgap compared to a much similar barrier layer that has neither nitrogen nor a cation thus improving thermal and electrical reliabilities. The nitrogen doped MgXO is non-stoichiometric whereas comparably, an oxynitride is stoichiometric. Example cations that may be used include aluminum, titanium, vanadium, chromium, and scandium.

Nitrogen doped oxides for lower bandgap

The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a first sensor disposed at a media facing surface (MFS) comprising at least one free layer, a second sensor disposed at the MFS comprising at least one free layer, a first spin generator spaced from the first sensor and recessed from the MFS, and a second spin generator spaced from the second sensor and recessed from the MFS. The first and second spin generators each individually comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise BiSb. The first and second sensors are configured to detect a read signal using a first voltage lead and a second voltage lead. The first and second spin generators are configured to inject spin current through non-magnetic layers to the first and second sensors using a plurality of current leads.

Non-localized spin valve multi-free-layer reader hybridized with spin orbit torque layers

The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.

Buffer layers and interlayers that promote BiSbx (012) alloy orientation for sot and MRAM devices

The present disclosure generally relates to a magnetic sensor half bridge circuit. The half bridge circuit comprises a bias source connected to a first leg and a second leg. The first leg comprises one or more first spin-orbit torque (SOT) structures connected in series, each first SOT structure comprising a first ferromagnetic (FM) layer disposed on a first SOT layer. The first SOT layer has a first end connected to ground and a second end connected to a first voltage sensor. The second leg comprises one or more second SOT structures connected in series, each second SOT structure comprising a second FM layer disposed on a second SOT layer. The second SOT layer has a first end connected to a second voltage sensor and a second end connected to a ground. The first voltage sensor is disposed adjacent to the second voltage sensor.

Magnetic sensor half-bridge based on inverse spin hall effect with reduced thermal drift

The present disclosure generally relates to a magnetic recording drive comprising a write head disposed over a media. The write head comprises a main pole, a waveguide disposed adjacent to the main pole, a near field transducer (NFT) coupled between the main pole and the waveguide at a media facing surface (MFS) and a head overcoat disposed on the MFS, the head overcoat comprising SiN. The head overcoat has an extinction coefficient (k) value of about 0.0. The media comprises a media overcoat disposed adjacent to the head overcoat. The media overcoat comprises a first layer of C and a second layer of SiN disposed on the first layer. The media overcoat has a k-value of about 0.5 or greater. The head overcoat is transparent while the media overcoat is heat absorbent.

Head and media overcoats for heat assisted magnetic recording

The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a sensor disposed at a media facing surface (MFS) and a spin generator spaced from the sensor and recessed from the MFS. The sensor and spin generators are disposed on a non-magnetic layer. The sensor comprises a free layer and the spin generator comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise topological material such as BiSb. The sensor is configured to detect a read signal using a first voltage lead and a second voltage lead. The spin generator is configured to inject spin current through the non-magnetic layer to the sensor using a first current lead and a second current lead. The shape of the non-magnetic layer is a triangular or trapezoidal shape to further concentrate spin current.

Non-localized spin valve reader hybridized with spin orbit torque layer

The present disclosure generally relates to a magnetic media drive comprising a magnetic recording head. The magnetic recording head comprises a main pole disposed at a media facing surface (MFS), a shield disposed at the MFS, a spin blocking layer disposed between the shield and the main pole, at least one non-magnetic layer disposed between the main pole and the shield, the at least one non-magnetic layer being disposed at the MFS, and at least one spin orbit torque (SOT) layer disposed over the at least one non-magnetic layer, the SOT layer being recessed a distance of about 20 nm to about 100 nm from the MFS. A ratio of a length of the SOT layer to a thickness of the SOT layer is greater than 1. The at least one SOT layer comprises BiSb.

Higher areal density non-local spin orbit torque (SOT) writer with topological insulator materials

The present disclosure generally relates to a magnetic recording head comprising one or more spin-orbit torque (SOT) devices, the SOT devices each comprising a bismuth antimony (BiSb) layer. The magnetic recording head comprises a SOT device comprising a first shield extending to a media facing surface (MFS), a seed layer disposed over the first shield, the seed layer being disposed at the MFS, a free layer disposed on the seed layer, the free layer being disposed at the MFS, a bismuth antimony (BiSb) layer disposed over the free layer, the BiSb layer being recessed from the MFS, a second shield disposed over the BiSb layer, the second shield extending to the MFS, and a shield notch coupled to the second shield, the shield notch being disposed between the first shield and the second shield. The magnetic recording head may be a two-dimensional magnetic recording head comprising two SOT devices.

Spin-orbit torque SOT reader with recessed spin hall effect layer

The present disclosure generally relates to a magnetic recording head comprising a spintronic device for magnetic media, such as a magnetic media drive. The spintronic device includes at least one spin Hall layer as well as at least one buffer layer and at least one interlayer. The buffer layer is positioned proximate a main pole of a write head while the interlayer is positioned proximate a trailing shield of the write head. The spin Hall layer is positioned between the buffer layer and the interlayer. The spintronic element may be disposed at the media facing surface (MFS) or recessed from the MFS. The spintronic device is capable of injecting spin current to the main pole, the trailing shield, or both.

Spin-orbit torque (SOT) writer with topological insulator materials

The present disclosure generally relates to a two dimensional magnetic recording (TDMR) spin-orbit torque (SOT) read head comprising bismuth antimony (BiSb) layers. The read head comprises a lower reader comprising a first SOT stack and an upper reader comprising a second SOT stack. The first SOT stack and the second SOT stack each individually comprise a BiSb layer recessed from a media facing surface (MFS) and a free layer exposed at the MFS. The BiSb layers of each SOT stack are recessed from the MFS a distance of about 5 nm to about 20 nm, the distance being less than a length of the free layers. In one embodiment, the lower reader and the upper reader share a current path. In another embodiment, the lower reader and the upper reader have separate current paths.

TDMR SOT read heads having recessed topological insulator materials

The present disclosure generally relates to a bismuth antimony (BiSb) based STO (spin torque oscillator) sensor. The STO sensor comprises a SOT device and a magnetic tunnel junction (MTJ) structure. By utilizing a BiSb layer within the SOT device, a larger spin Hall angle (SHA) can be achieved, thereby improving the efficiency and reliability of the STO sensor.

Topological insulator based spin torque oscillator reader

The present disclosure generally relate to spin-orbit torque (SOT) devices. The SOT devices each comprise a non-magnetic layer, a free layer disposed in contact with the non-magnetic layer, and a bismuth antimony (BiSb) layer disposed over the free layer. The non-magnetic layer has a thickness of about 0.5 nm to about 2 nm. The BiSb layer has a thickness of about 5 nm to about 10 nm. The BiSb layer and the free layer have collective thickness between about 5 nm to about 20 nm. By reducing the thickness of the non-magnetic layer and BiSb layer, a read gap of each SOT device is reduced while enabling large inverse spin Hall angles and high signal-to-noise ratios.

SOT reader using BiSb topological insulator

The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device comprising a first seed layer, a first spin hall effect (SHE) layer, a first interlayer, a first free layer, a gap layer, a second seed layer, a second SHE layer, a second free layer, and a second interlayer. The gap layer is disposed between the first SHE layer and the second SHE layer. The materials and dimensions used for the first and second seed layers, the first and second interlayers, and the first and second SHE layers affect the resulting spin hall voltage converted from spin current injected from the first free layer and the second free layer, as well as the ability to tune the first and second SHE layers. Moreover, the SOT differential reader improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).

SOT film stack for differential reader

Growing community of inventors

Kodaira, Japan

Hisashi Takano