The dominancy of damping like torque for the current induced magnetization switching in Pt/Co/W multilayers

High‐Efficiency Spin–Orbit Torque Switching Using a Single Heavy‐Metal Alloy with Opposite Spin Hall Angles

“…From Equation (), the values of the extracted damping‐like H DL and field‐like H FL effective field as a function of V in using the following relation [ 6,17,47 ] …”

“…where ξ is the ratio of the planar Hall effect ( R PHE ) and anomalous Hall effect ( R H ) resistance (ξ = R PHE / R H ), the ± sign corresponds to the magnetization pointing up and down (± M z ) along the out‐of‐plane axis. [ 6,47,48 ] The ratio ξ value of Pt 1.00 Gd 0.00 , Pt 0.98 Gd 0.02 , Pt 0.86 Gd 0.14 , Pt 0.70 Gd 0.30 , and Pt 0.67 Gd 0.33 devices are obtained as 0.08, 0.16, 0.16, 0.19, and 0.28, respectively. The R PHE was obtained by rotating the sample in the plane from 0° to 360° relative to the direction of the applied magnetic field direction ( H x ), which are summarized in Figure S5 of the Supporting Information.…”

“…The generated spin current can be transmitted into the adjacent FM layer, and the resulting torque can switch the magnetization of FM layer. [ 5,6,16–18 ]…”

“…Importantly, HMs are the most widely used materials in SOT devices due to their strong intrinsic SOC. [ 1–6 ] However, these materials have a very expensive, scares of resources and consequently there has been a request to find alternative materials with less expensive and can exhibit a larger θ SHA than pure HMs. As compared to the conventional pure heavy metals Pt, Ta, W, or Hf, recent investigations have reported larger θ SHA in metallic alloys like MnPt, [ 19 ] AuPt, [ 20 ] CuPt, [ 21 ] AuTa, [ 22 ] and CuIr, [ 23 ] due to the enhancement of the extrinsic spin Hall effect (SHE), which is mainly connected with the spin‐dependent scattering on impurities or defects, namely, skew scattering and/or the side jump.…”

“…One of the ultimate goals of spintronics is to manipulate magnetism through electrical means. [1] Compared with the conventional spin-transfer torque (STT) that using the spin-polarized current to transfer angular momentum from a ferromagnet (FM) to another one, [2] the spin-orbit torque (SOT) that driven by in-plane currents flowing in heavy metals (HMs), [3][4][5][6] topological insulators, [7][8][9] antiferromagnets, [10][11][12][13] or Weyl semimetals, [14][15] opens a more efficient way to tune magnetization. To build energy-efficient SOT devices, a tremendous amount of work has been devoted to engineering spin-orbit coupling (SOC) strength via either the bulk spin Hall or interfacial Rashba effect.…”