Western Digital Technologies, Inc.

Susumu Okamura

Brian Rodrick York

James Mac Freitag

Quang Le

Cherngye Hwang

Kuok San Ho

Yuankai Zheng

Xiaoyong Liu

Christian Kaiser

Hisashi Takano

Suping Song

Ning Shi

Michael Gribelyuk

Randy G Simmons

Alexander Goncharov

Muhammad Asif Bashir

Zhitao Diao

Yongchul Ahn

Xinjiang Shen

Xiaoyu Xu

Aspects of the present disclosure generally relate to magnetic recording heads (such as write heads of data storage devices) that include multilayer structures to facilitate targeted switching and relatively low coercivity. In one or more embodiments, a magnetic recording head includes an iron-cobalt (FeCo) layer having a crystalline structure that is a cubic lattice structure, a first crystalline layer formed of a first material, and a second crystalline layer between the first crystalline layer and the FeCo layer. The second crystalline layer is formed of a second material different from the first material, and the second crystalline layer interfaces both the FeCo layer and the first crystalline layer. The crystalline structure of the FeCo layer has a texture of <100>.

Multilayer structures for magnetic recording devices to facilitate targeted magnetic switching and low coercivity

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 magnetoresistive (MR) devices. The MR device comprises a synthetic antiferromagnetic (SAF) layer that increases exchange coupling field, and in turn, less magnetic noise of such devices. The MR device comprises a first ferromagnetic (FM1) layer and a second ferromagnetic (FM2) layer, in between which is an SAF spacer of RuAl alloy having a B2 crystalline structure which may grow epitaxial on BCC (110) or FCC (111) textures, meaning that the (110) or (111) plane is parallel to the surface of MR device substrate. Further, amorphous layers may be inserted into the device structure to reset the growth texture of the device to a (001), (110), or (111) texture in order to promote the growth of tunneling barrier layers or antiferromagnetic (AF) pinning layers.

Magnetoresistive devices comprising a synthetic antiferromagnetic coupling layer of RuAl having a (110) texture

The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprise one or more GeNiFe layers, where at least one GeNiFe layer is disposed in contact with the BiSb layer. The GeNiFe layer has a thickness less than or equal to about 15 Å when used as an interlayer on top of the BiSb layer or less than or equal to 40 Å when used as a buffer layer underneath the BiSb. When the BiSb layer is doped with a dopant comprising a gas, a metal, a non-metal, or a ceramic material, the GeNiFe layer promotes the BiSb layer to have a (012) orientation. When the BiSb layer is undoped, the GeNiFe layer promotes the BiSb layer to have a (001) orientation. Utilizing the GeNiFe layer allows the crystal orientation of the BiSb layer to be selected.

Doped BiSb (012) or undoped BiSb (001) topological insulator with GeNiFe buffer layer and/or interlayer for SOT based sensor, memory, and storage devices

Embodiments of the present disclosure generally relate to a read sensor utilized in a read head. The read sensor comprises an amorphous break layer disposed on a shield, a seed layer disposed on the amorphous break layer, a first ferromagnetic layer disposed on the seed layer, a barrier layer disposed on the first ferromagnetic layer, and a second ferromagnetic layer disposed on the barrier layer. The amorphous break layer comprises CoFeBTa, the seed layer comprises RuAl, and the barrier layer comprises a semiconductor material, such as ZnSe, ZnTe, ZnO, CuSe, or CuInGaSe. The semiconductor barrier layer reduces the resistance-area product of the read sensor. The amorphous break layer breaks the texture between the shield, which has a FCC texture, and the seed layer, which has a BCC texture. The BCC texture of the seed layer is then inherited by the remaining layers disposed over the seed layer.

Read sensor with ordered heusler alloy free layer and semiconductor barrier layer

The present disclosure generally relates to a spin torque element disposed between a main pole and a shield in a magnetic recording head. The shield could be a trailing shield, a side shield, or a leading shield. The spin torque element includes a dual layer spin transfer structure that is spaced from magnetic layers on either side using spacer layers. One magnetic layer that faces a positive polarizer has a positive polarization while another magnetic layer facing the negative polarizer has a negative polarization. As such, torque in the spacer layers is maximized when the direction of the magnetization in the STL is opposite to the gap field.

Recording head with a multilayer spin torque element having positive and negative beta materials

The present disclosure generally relates to magnetoresistive (MR) devices. The MR device comprises a synthetic antiferromagnetic (SAF) layer that increases stability to magnetic fields, and in turn, results in lower magnetic noise of the device. The MR device comprises a first ferromagnetic (FM1) layer and a second ferromagnetic (FM2) layer, in between which is an SAF spacer of RuAl alloy having a B2 crystalline structure with (001) texture, meaning that the (001) plane is parallel to the surface of MR device substrate. The first ferromagnetic (FM1) layer and a part of the second ferromagnetic (FM2) layer also have the (001) texture. An amorphous layer in a second ferromagnetic (FM2) layer can reset the growth texture of the MR device to a (111) texture in order to promote the growth of an antiferromagnetic (AF) pinning layer.

Magnetoresistive device comprising a synthetic antiferromagnetic coupling layer of RuAl having a (001) texture

Embodiments of the present disclosure relate to a cobalt-boron (CoB) layer for magnetic recording devices, memory devices, and storage devices. In one or more embodiments, the CoB layer is part of a spin-orbit torque (SOT) device. In one or more embodiments, the SOT device is part of an SOT based sensor, an SOT based writer, a memory device (such as a magnetoresistive random-access memory (MRAM) device), and/or a storage device (such as a hard disk drive (HDD) or a tape drive). In one embodiment, an SOT device includes a seed layer, and a cap layer spaced from the seed layer. The SOT device includes a spin-orbit torque (SOT) layer, and a nano layer (NL) between the seed layer and the cap layer. The SOT device includes a cobalt-boron (CoB) layer between the seed layer and the cap layer, and the CoB layer is ferromagnetic.

Cobalt-boron (CoB) layer for magnetic recording devices, memory devices, and storage devices

A tunneling magnetoresistance (TMR) device has an improved seed layer for the lower or first ferromagnetic layer that eliminates the need for boron in the two ferromagnetic layers. The seed layer, for example a RuAl alloy, has a B2 crystalline structure with (001) texture when deposited on an amorphous pre-seed layer, meaning that the (001) plane is parallel to the surface of the TMR device substrate. The subsequently deposited first ferromagnetic layer, like a CoFe alloy, and the tunneling barrier layer, typically MgO, inherit the (001) texture of the seed layer.

Tunneling magnetoresistive (TMR) device with improved seed layer

Embodiments of the present disclosure generally relate to spintronic devices, and more specifically to self-cooling spintronic devices. In an embodiment, a device is provided. The device includes a spintronic device having a first side and a second side opposite the first side, a first layer disposed on the first side, and a second layer disposed on the second side, the first layer having a Seebeck coefficient that is different from a Seebeck coefficient of the second layer.

Spintronic devices with self-cooling function

The present disclosure generally relate to spin-orbit torque (SOT) devices comprising a topological insulator (TI) modulation layer. The TI modulation layer comprises a plurality of bismuth or bismuth-rich composition modulation layers, a plurality of TI lamellae layers comprising BiSb having a (012) crystal orientation, and a plurality of texturing layers. The TI lamellae layers comprise dopants or clusters of atoms, the clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material. The clusters of atoms are configured to have a grain boundary glass forming temperature of less than about 400° C. Doping the TI lamellae layers comprising BiSb having a (012) crystal orientation with clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material enable the SOT MTJ device to operate at higher temperatures while inhibiting migration of Sb from the BiSb of the TI lamellae layers.

BiSbX (012) layers having increased operating temperatures for SOT and MRAM devices

The present disclosure generally relates to a magnetic recording head comprising a spintronic device. The spintronic device is disposed between a main pole and a trailing shield of the magnetic recording head. The spintronic device comprises a multilayer spacer layer comprising a Cu layer in contact with a spin torque layer and a spin transparent texture layer disposed on the Cu layer, the spin transparent texture layer comprising AgSn or AgZn. A multilayer notch comprising a CoFe layer is disposed over the spin transparent texture layer of the multilayer spacer layer and a Heusler alloy layer is disposed on the CoFe layer, the Heusler alloy layer comprising CoMnGe, CoFeGe, or CoFeMnGe. The multilayer spacer layer and the multilayer notch result in the spintronic device having a high spin polarization and a reduced critical current.

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San Jose, CA, United States of America

Susumu Okamura