We investigated temperature dependent current driven spin-orbit torques in magnetron sputtered Ru2Sn3 (4 and 10 nm)/Co20Fe60B20 (5 nm) layered structures with in-plane magnetic anisotropy. The room temperature dampinglike and fieldlike spin torque efficiencies of the amorphous Ru2Sn3 films were measured to be 0.14±0.008(0.07±0.012) and -0.03±0.006(-0.20±0.009), for the four (10 nm) films, respectively, by utilizing the second-harmonic Hall technique. The large fieldlike torque in the relatively thicker Ru2Sn3 (10 nm) thin film is unique compared to the traditional spin Hall materials interfaced with thick magnetic layers with in-plane magnetic anisotropy which typically have dominant dampinglike and negligible fieldlike torques. Additionally, the observed room temperature fieldlike torque efficiency in Ru2Sn3 (10 nm)/CoFeB (5 nm) is up to three times larger than the dampinglike torque (-0.20±0.009 and 0.07±0.012, respectively) and 30 times larger at 50 K (-0.29±0.014 and 0.009±0.017, respectively). The temperature dependence of the fieldlike torques shows dominant contributions from the intrinsic spin Hall effect while the dampinglike torques show dominate contributions from the extrinsic spin Hall effects, skew scattering, and side jump. Through macrospin calculations, we found that including fieldlike torques on the order of or larger than the dampinglike torque can reduce the switching critical current and decrease magnetization procession for a perpendicular ferromagnetic layer.
Bibliographical noteFunding Information:
This work was supported in part by ASCENT, one of six centers in JUMP, a Semiconductor Research Corporation (SRC) program sponsored by DARPA. This material is based upon work supported in part by the National Science Foundation under the Scalable Parallelism in the Extreme (SPX) Grant under Award No. CCF-1725420. The TEM was performed by Dr. Jason Myers and the RBS was performed by Dr. Greg Haugstad in the College of Science and Engineering (CSE) Characterization Facility at the University of Minnesota (UMN), supported in part by the NSF through the UMN MRSEC program. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award No. ECCS-2025124.
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