Despite their great promise for providing a pathway for very efficient and fast manipulation of magnetization, spin‐orbit torque (SOT) operations are currently energy inefficient due to a low damping‐like SOT efficiency per unit current bias, and/or the very high resistivity of the spin Hall materials. This work reports an advantageous spin Hall material, Pd1−
- Award ID(s):
- 1719875
- NSF-PAR ID:
- 10325362
- Date Published:
- Journal Name:
- Applied Physics Reviews
- Volume:
- 9
- Issue:
- 2
- ISSN:
- 1931-9401
- Page Range / eLocation ID:
- 021402
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Spin‐orbit torques generated by exfoliated layers of the low‐symmetry semi‐metal ZrTe3are measured using the spin‐torque ferromagnetic resonance (ST‐FMR) technique. When the ZrTe3has a thickness greater than about 10 nm, artifacts due to spin pumping and/or resonant heating can cause the standard ST‐FMR analysis to overestimate the true magnitude of the torque efficiency by as much as a factor of 30, and to indicate incorrectly that the spin‐orbit torque depends strongly on the ZrTe3layer thickness. Artifact‐free measurements can still be achieved over a substantial thickness range by the method developed recently to detect ST‐FMR signals in the Hall geometry as well as the longitudinal geometry. ZrTe3/Permalloy samples generate a conventional in‐plane anti‐damping spin torque efficiency = 0.014 ± 0.004, and an unconventional in‐plane field‐like torque efficiency = 0.003 ± 0.001. The out‐of‐plane anti‐damping torque is negligible. It is suggested that artifacts similarly interfere with the standard ST‐FMR analysis for other van der Waals samples thicker than about 10 nm.