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Spin–orbit-torque engineering via oxygen manipulation

Nature Nanotechnology volume 10, pages 333–338 (2015)Cite this article

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Abstract

Spin transfer torques allow the electrical manipulation of magnetization at room temperature, which is desirable in spintronic devices such as spin transfer torque memories. When combined with spin–orbit coupling, they give rise to spin–orbit torques, which are a more powerful tool for controlling magnetization and can enrich device functionalities. The engineering of spin–orbit torques, based mostly on the spin Hall effect, is being intensely pursued. Here, we report that the oxidation of spin–orbit-torque devices triggers a new mechanism of spin–orbit torque, which is about two times stronger than that based on the spin Hall effect. We thus introduce a way to engineer spin–orbit torques via oxygen manipulation. Combined with electrical gating of the oxygen level, our findings may also pave the way towards reconfigurable logic devices.

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Figure 1: Device structure and the effect of SiO2 capping layer thickness.
Figure 2: SIMS, XPS, XAS, VSM and XMCD characterization.
Figure 3: CoFeB oxidation effect.
Figure 4: CoFeB thickness effect.
Figure 5: Material and structural dependence of sign reversal.

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Acknowledgements

This research is supported by the National Research Foundation (NRF), Prime Minister's Office, Singapore, under its Competitive Research Programme (CRP award no. NRF-CRP12-2013-01 and NRF-CRP4-2008-06). K.L. acknowledges financial support from NRF (NRF-2013R1A2A2A01013188) and the MEST Pioneer Research Center Program (2011-0027905). H.W.L. acknowledges financial support from NRF (NRF-2011-0030046 and NRF-2013R1A2A2A05006237) and MOTIE (10044723). D.Y., W.N. and J.P. acknowledge financial support by the NCRI Program (2009-0081576) and MPK Program (2011-0031558) through the NRF funded by the Ministry of Science, Information Communication Technology, and Future Planning, Korea (MSIP). P.A.L. is supported by Pohang University of Science and Technology and MSIP.

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Authors and Affiliations

  1. Department of Electrical and Computer Engineering, and NUSNNI-Nanocore, National University of Singapore, Singapore 117576, Singapore

    Xuepeng Qiu, Kulothungasagaran Narayanapillai, Yang Wu, Praveen Deorani & Hyunsoo Yang

  2. c_CCMR and Department of Physics, Pohang University of Science and Technology, Pohang, 790-784, Korea

    Dong-Hyuk Yang, Woo-Suk Noh & Jae-Hoon Park

  3. Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang, 790-784, Korea

    Jae-Hoon Park

  4. Department of Materials Science and Engineering, Korea University, Seoul, 136-701, Korea

    Kyung-Jin Lee

  5. KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-713, Korea

    Kyung-Jin Lee

  6. PCTP and Department of Physics, Pohang University of Science and Technology, Pohang, 790-784, Korea

    Hyun-Woo Lee

Authors
  1. Xuepeng Qiu
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Contributions

X.Q. and H.Y. planned the study. X.Q. and K.N. fabricated devices. X.Q. measured transport properties. Y.W. helped with characterization. D-H.Y., W-S.N. and J-H.P. carried out X-ray measurements. All authors discussed the results. X.Q., K-J.L., H-W.L. and H.Y. wrote the manuscript. H.Y. supervised the project.

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Correspondence to Hyunsoo Yang.

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Qiu, X., Narayanapillai, K., Wu, Y. et al. Spin–orbit-torque engineering via oxygen manipulation. Nature Nanotech 10, 333–338 (2015). https://doi.org/10.1038/nnano.2015.18

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