Journal Article

FZJ-2022-01844

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Tuning Spin‐Orbit Torques Across the Phase Transition in VO 2 /NiFe Heterostructure

Kim, J.-y. ; Cramer, J. ; Lee, K. ; Han, D.-S. ; Go, D.FZJ* ; Salev, P. ; Lapa, P. N. ; Vargas, N. M. ; Schuller, I. K. ; Mokrousov, Y.FZJ* ; Jakob, G. ; Kläui, M. (Corresponding author)

2022
Wiley-VCH Weinheim

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Please use a persistent id in citations: http://hdl.handle.net/2128/31391  doi:10.1002/adfm.202111555

Abstract: 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 VO2/NiFe heterostructures are investigated using spin-torque ferromagnetic resonance, where the VO2 layer undergoes a prominent insulator-metal transition. A roughly twofold increase in the Gilbert damping parameter, α, with temperature is attributed to the change in the VO2/NiFe interface spin absorption across the VO2 phase transition. More remarkably, a large modulation (±100%) and a sign change of the current-induced spin-orbit torque across the VO2 phase transition suggest two competing spin-orbit torque generating mechanisms. The bulk spin Hall effect in metallic VO2, corroborated by the first-principles calculation of the spin Hall conductivity σSH≈−104(ℏe)Ω−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, with opposite sign and a similar magnitude to the bulk spin Hall effect in metallic VO2, can 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 that undergo phase transitions for new device functionalities.

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (IAS-1)
2. Quanten-Theorie der Materialien (PGI-1)
3. JARA-FIT (JARA-FIT)
4. JARA - HPC (JARA-HPC)

Research Program(s):

1. 5211 - Topological Matter (POF4-521) (POF4-521)

Appears in the scientific report 2022

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 15 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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