Tuning spin-orbit torques across the phase transition in VO2/NiFe heterostructure
| Autor: | Jun‐young Kim, Joel Cramer, Kyujoon Lee, Dong‐Soo Han, Dongwook Go, Pavel Salev, Pavel N. Lapa, Nicolas M. Vargas, Ivan K. Schuller, Yuriy Mokrousov, Gerhard Jakob, Mathias Kläui |
|---|---|
| Přispěvatelé: | Mainz, Johannes Gutenberg-Universität |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Biomaterials
Condensed Matter - Materials Science 530 Physics Electrochemistry Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences ddc:530 Condensed Matter::Strongly Correlated Electrons Astrophysics::Earth and Planetary Astrophysics Condensed Matter Physics 530 Physik Electronic Optical and Magnetic Materials |
| Zdroj: | Advanced functional materials 32(17), 2111555 (2022). doi:10.1002/adfm.202111555 Advanced Functional Materials |
| DOI: | 10.25358/openscience-7331 |
| Popis: | The emergence of spin-orbit torques as a promising approach to energy-efficient magnetic switching has generated large interest in material systems with easily and fully tunable spin-orbit torques. Here, current-induced spin-orbit torques in VO$_2$/NiFe heterostructures were investigated using spin-torque ferromagnetic resonance, where the VO$_2$ layer undergoes a prominent insulator-metal transition. A roughly two-fold increase in the Gilbert damping parameter, $\alpha$, with temperature was attributed to the change in the VO$_2$/NiFe interface spin absorption across the VO$_2$ phase transition. More remarkably, a large modulation ($\pm$100%) and a sign change of the current-induced spin-orbit torque across the VO$_2$ phase transition suggest two competing spin-orbit torque generating mechanisms. The bulk spin Hall effect in metallic VO$_2$, corroborated by our first-principles calculation of spin Hall conductivity, $\sigma_{SH} \approx 10^4 \frac{\hbar}{e} \Omega^{-1} m^{-1}$, is verified as the main source of the spin-orbit torque in the metallic phase. The self-induced/anomalous torque in NiFe, of the opposite sign and a similar magnitude to the bulk spin Hall effect in metallic VO$_2$, could be the other competing mechanism that dominates as temperature decreases. For applications, the strong tunability of the torque strength and direction opens a new route to tailor spin-orbit torques of materials which undergo phase transitions for new device functionalities. Comment: 16 pages, 5 figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|