Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems

We report the enhanced spin-orbit torque (SOT) effect due to the rare-earth metal Tb in a Pt/[Co/Ni]2/Co/Tb multilayer with perpendicular magnetic anisotropy (PMA). Due to the large spin-orbit coupling in Tb, the effective dampinglike efficiency, ξeffDL, is determined to be 0.55 for 9-nm Tb as compa...

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Main Authors: Lew, Wen Siang, Wong, Qi Ying, Murapaka, Chandrasekhar, Law, Wai Cheung, Gan, Wei Liang, Lim, Gerard Joseph
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2019
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Online Access:https://hdl.handle.net/10356/85743
http://hdl.handle.net/10220/48233
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-857432023-02-28T19:33:34Z Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems Lew, Wen Siang Wong, Qi Ying Murapaka, Chandrasekhar Law, Wai Cheung Gan, Wei Liang Lim, Gerard Joseph School of Physical and Mathematical Sciences Magnetism Materials Science DRNTU::Science::Physics We report the enhanced spin-orbit torque (SOT) effect due to the rare-earth metal Tb in a Pt/[Co/Ni]2/Co/Tb multilayer with perpendicular magnetic anisotropy (PMA). Due to the large spin-orbit coupling in Tb, the effective dampinglike efficiency, ξeffDL, is determined to be 0.55 for 9-nm Tb as compared to ξeffDL=0.18 for the reference Pt/[Co/Ni]2/Co/Ta stack. A relatively large effective spin Hall efficiency of Tb, θeffSH,Tb, is determined to be −0.480 for Tbwith a 9-nm thickness through a Hz-biased harmonic measurement. Enhanced magnetization switching efficiency is observed with increasing Tb thickness, affirming the sizable antidamping torque responsible for deterministic switching. Furthermore, due to a more substantial interfacial coupling in Co/Tb interface than in Co/Ta interface, strong angular dependence of the dampinglike and fieldlike terms is, but diminishes with increasing Tb thickness. These results affirm that Tb plays a significant role in tuning the SOT efficiency in these structures as the increased Tb concentration leads to an enhancement of the effective spin Hall angle and switching efficiency. NRF (Natl Research Foundation, S’pore) Published version 2019-05-16T07:18:36Z 2019-12-06T16:09:26Z 2019-05-16T07:18:36Z 2019-12-06T16:09:26Z 2019 Journal Article Wong, Q. Y., Murapaka, C., Law, W. C., Gan, W. L., Lim, G. J., & Lew, W. S. (2019). Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems. Physical Review Applied, 11(2), 024057-. doi:10.1103/PhysRevApplied.11.024057 https://hdl.handle.net/10356/85743 http://hdl.handle.net/10220/48233 10.1103/PhysRevApplied.11.024057 en Physical Review Applied © 2019 American Physical Society. All rights reserved. This paper was published in Physical Review Applied and is made available with permission of American Physical Society. 10 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Magnetism
Materials Science
DRNTU::Science::Physics
spellingShingle Magnetism
Materials Science
DRNTU::Science::Physics
Lew, Wen Siang
Wong, Qi Ying
Murapaka, Chandrasekhar
Law, Wai Cheung
Gan, Wei Liang
Lim, Gerard Joseph
Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
description We report the enhanced spin-orbit torque (SOT) effect due to the rare-earth metal Tb in a Pt/[Co/Ni]2/Co/Tb multilayer with perpendicular magnetic anisotropy (PMA). Due to the large spin-orbit coupling in Tb, the effective dampinglike efficiency, ξeffDL, is determined to be 0.55 for 9-nm Tb as compared to ξeffDL=0.18 for the reference Pt/[Co/Ni]2/Co/Ta stack. A relatively large effective spin Hall efficiency of Tb, θeffSH,Tb, is determined to be −0.480 for Tbwith a 9-nm thickness through a Hz-biased harmonic measurement. Enhanced magnetization switching efficiency is observed with increasing Tb thickness, affirming the sizable antidamping torque responsible for deterministic switching. Furthermore, due to a more substantial interfacial coupling in Co/Tb interface than in Co/Ta interface, strong angular dependence of the dampinglike and fieldlike terms is, but diminishes with increasing Tb thickness. These results affirm that Tb plays a significant role in tuning the SOT efficiency in these structures as the increased Tb concentration leads to an enhancement of the effective spin Hall angle and switching efficiency.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Lew, Wen Siang
Wong, Qi Ying
Murapaka, Chandrasekhar
Law, Wai Cheung
Gan, Wei Liang
Lim, Gerard Joseph
format Article
author Lew, Wen Siang
Wong, Qi Ying
Murapaka, Chandrasekhar
Law, Wai Cheung
Gan, Wei Liang
Lim, Gerard Joseph
author_sort Lew, Wen Siang
title Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
title_short Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
title_full Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
title_fullStr Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
title_full_unstemmed Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
title_sort enhanced spin-orbit torques in rare-earth pt/[co/ni]2/co/tb systems
publishDate 2019
url https://hdl.handle.net/10356/85743
http://hdl.handle.net/10220/48233
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