scholarly journals Theoretical Study of Field-Free Switching in PMA-MTJ Using Combined Injection of STT and SOT Currents

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1345
Author(s):  
Shaik Wasef ◽  
Hossein Fariborzi
Keyword(s):  
Critical Current ◽  
Theoretical Study ◽  
Tunnel Junctions ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Orbit ◽  
Micromagnetic Simulations ◽  
Spintronic Devices ◽  
Current Densities ◽  
The Relationship

Field-free switching in perpendicular magnetic tunnel junctions (P-MTJs) can be achieved by combined injection of spin-transfer torque (STT) and spin-orbit torque (SOT) currents. In this paper, we derived the relationship between the STT and SOT critical current densities under combined injection. We included the damping–like torque (DLT) and field-like torque (FLT) components of both the STT and SOT. The results were derived when the ratio of the FLT to the DLT component of the SOT was positive. We observed that the relationship between the critical SOT and STT current densities depended on the damping constant and the magnitude of the FLT component of the STT and the SOT current. We also noted that, unlike the FLT component of SOT, the magnitude and sign of the FLT component of STT did not have a significant effect on the STT and SOT current densities required for switching. The derived results agreed well with micromagnetic simulations. The results of this work can serve as a guideline to model and develop spintronic devices using a combined injection of STT and SOT currents.

scholarly journals Single-shot dynamics of spin–orbit torque and spin transfer torque switching in three-terminal magnetic tunnel junctions

2020 ◽  
Vol 15 (2) ◽  
pp. 111-117 ◽  
Author(s):  
Eva Grimaldi ◽  
Viola Krizakova ◽  
Giacomo Sala ◽  
Farrukh Yasin ◽  
Sébastien Couet ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Single Shot ◽  
Spin Orbit

The dependence of critical current density of GdFeCo layer on composition of thermally assisted STT-RAM

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744075
Author(s):  
B. Dai ◽  
J. Zhu ◽  
K. Liu ◽  
L. Yang ◽  
J. Han
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Anisotropy Constant ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Text Memory ◽  
Effective Anisotropy Constant ◽  
Current Densities ◽  
Magneto Resistance

Amorphous rare earth–transitional metal (RETM) GdFeCo memory layer with RE- and TM-rich compositions was fabricated in stacks of GdFeCo (10 nm)/Cu (3 nm)/[Co(0.2 nm)/Pd(0.4 nm)]6. Their magnetic properties and spin transfer torque (STT) switching of magnetization were investigated. The maximum magneto-resistance (MR) was around 0.24% for the TM-rich Gd[Formula: see text] (Fe[Formula: see text]Co[Formula: see text])[Formula: see text] memory layer and was −0.03% for the RE-rich Gd[Formula: see text] (Fe[Formula: see text]Co[Formula: see text])[Formula: see text] memory layer. The critical current densities [Formula: see text] to switch the GdFeCo memory layers are in the range of [Formula: see text] A/cm2–[Formula: see text] A/cm2. The dependence of critical current density [Formula: see text] and effective anisotropy constant [Formula: see text] on Gd composition were also investigated. Both [Formula: see text] and [Formula: see text] have maximum values in the Gd composition range from 21–29 at.%, suitable for thermally assisted STT-RAM for storage density exceeding Gb/inch2.

scholarly journals Single-shot dynamics of spin-orbit torque and spin transfer torque switching in three-terminal magnetic tunnel junctions

2020 ◽  
Author(s):  
Viola Krizakova ◽  
Eva Grimaldi ◽  
Giacomo Sala ◽  
Farrukh Yasin ◽  
Sébastien Couet ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Single Shot ◽  
Spin Orbit

scholarly journals Reducing Dzyaloshinskii-Moriya interaction and field-free spin-orbit torque switching in synthetic antiferromagnets

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ruyi Chen ◽  
Qirui Cui ◽  
Liyang Liao ◽  
Yingmei Zhu ◽  
Ruiqi Zhang ◽  
...  
Keyword(s):  
Domain Wall ◽  
Tunnel Junctions ◽  
Low Power Consumption ◽  
Stray Field ◽  
Magnetic Memory ◽  
Spin Orbit ◽  
Theoretic Analysis ◽  
Spintronic Devices ◽  
Deterministic Switching ◽  
Moriya Interaction

AbstractPerpendicularly magnetized synthetic antiferromagnets (SAF), possessing low net magnetization and high thermal stability as well as easy reading and writing characteristics, have been intensively explored to replace the ferromagnetic free layers of magnetic tunnel junctions as the kernel of spintronic devices. So far, utilizing spin-orbit torque (SOT) to realize deterministic switching of perpendicular SAF have been reported while a large external magnetic field is typically needed to break the symmetry, making it impractical for applications. Here, combining theoretic analysis and experimental results, we report that the effective modulation of Dzyaloshinskii-Moriya interaction by the interfacial crystallinity between ferromagnets and adjacent heavy metals plays an important role in domain wall configurations. By adjusting the domain wall configuration between Bloch type and Néel type, we successfully demonstrate the field-free SOT-induced magnetization switching in [Co/Pd]/Ru/[Co/Pd] SAF devices constructed with a simple wedged structure. Our work provides a practical route for utilization of perpendicularly SAF in SOT devices and paves the way for magnetic memory devices with high density, low stray field, and low power consumption.

Materials, Devices and Spin Transfer Torque in Antiferromagnetic Spintronics: A Concise Review

SPIN ◽  
2017 ◽  
Vol 07 (03) ◽  
pp. 1740014 ◽  
Author(s):  
Cormac Ó Coileáin ◽  
Han Chun Wu
Keyword(s):  
Magnetic Fields ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Tetragonal Structure ◽  
Next Generation ◽  
Tunnel Magnetoresistance ◽  
Spintronic Devices ◽  
Concise Review ◽  
Plane Anisotropy ◽  
Magnetic States

From historical obscurity, antiferromagnets are recently enjoying revived interest, as antiferromagnetic (AFM) materials may allow the continued reduction in size of spintronic devices. They have the benefit of being insensitive to parasitic external magnetic fields, while displaying high read/write speeds, and thus poised to become an integral part of the next generation of logical devices and memory. They are currently employed to preserve the magnetoresistive qualities of some ferromagnetic based giant or tunnel magnetoresistance systems. However, the question remains how the magnetic states of an antiferromagnet can be efficiently manipulated and detected. Here, we reflect on AFM materials for their use in spintronics, in particular, newly recognized antiferromagnet Mn2Au with its in-plane anisotropy and tetragonal structure and high Néel temperature. These attributes make it one of the most promising candidates for AFM spintronics thus far with the possibility of architectures freed from the need for ferromagnetic (FM) elements. Here, we discuss its potential for use in ferromagnet-free spintronic devices.

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