Western Digital Technologies, Inc.

Tokyo Institute of Technology

Son T Le

Quang Le

Xiaoyong Liu

Cherngye Hwang

Brian Rodrick York

Hisashi Takano

Nam Hai Pham

Kuok San Ho

Fan Tuo

Rohan Babu Nagabhirava

Hassan Osman

Huy H Ho

Michael Gribelyuk

Maki Maeda

Xiaoyu Xu

Randy G Simmons

Andrew Chen

Alan Spool

Sharon Swee Ling Banh

Xing-Cai Guo

Yu Tao

Jinming Liu

Julian Sasaki

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 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 spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprises a first shield, a BiSb layer disposed over the first shield (S), a free layer (FL) disposed over the BiSb layer, and a second shield (S) disposed over the FL. The S, the FL, and the Sare disposed at a media facing surface (MFS). The BiSb layer is recessed from the MFS a first distance of about 5 nm to about 20 nm. The FL has a length greater than the first distance. A notch and/or an insulation layer is disposed adjacent to the BiSb layer at the MFS. Current may be configured to flow vertically through the Sto the FL, and horizontally from the FL to the BiSb layer. Current may be configured to flow vertically through the Sto the S

SOT reader with recessed SOT topological insulator material

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 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

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San Jose, CA, United States of America

Son T Le