Please use this identifier to cite or link to this item:
Title: Enhanced spin-orbit torques in rare-earth Pt/[Co/Ni]2/Co/Tb systems
Authors: Lew, Wen Siang
Wong, Qi Ying
Murapaka, Chandrasekhar
Law, Wai Cheung
Gan, Wei Liang
Lim, Gerard Joseph
Keywords: Magnetism
Materials Science
Issue Date: 2019
Source: 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
Series/Report no.: Physical Review Applied
Abstract: 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.
DOI: 10.1103/PhysRevApplied.11.024057
Rights: © 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.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SPMS Journal Articles

Files in This Item:
File Description SizeFormat 
Enhanced spin-orbit torques in rare-earth Pt [CoNi] 2CoTb systems.pdf2.64 MBAdobe PDFThumbnail

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.