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Manipulating exchange bias by spin–orbit torque

Nature Materials volume 18, pages 335–341 (2019)Cite this article

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Abstract

Exchange bias, a shift in the hysteresis loop of a ferromagnet arising from interfacial exchange coupling between adjacent ferromagnetic and antiferromagnetic layers, is an integral part of spintronic devices. Here, we show that spin–orbit torque generated from spin current, a promising approach to switch the ferromagnetic magnetization of next-generation magnetic random access memory, can also be used to manipulate the exchange bias. Applying current pulses to a Pt/Co/IrMn trilayer causes concurrent switching of ferromagnetic magnetization and exchange bias, but with different underlying mechanisms. This implies that the ferromagnetic magnetization and exchange bias can be manipulated independently. Our work demonstrates that spin–orbit torque in ferromagnet/antiferromagnet heterostructures facilitates independent manipulations of distinct magnetic properties, motivating innovative designs for future spintronics devices.

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Fig. 1: Concurrent SOT switching for FM magnetization and exchange bias.
Fig. 2: Thickness dependence of exchange bias reversal in SOT switching.
Fig. 3: Effects of current direction and longitudinal magnetic field on SOT switching in the antiparallel state (AP-mode)
Fig. 4: Independent SOT switching of FM magnetization and exchange bias.

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Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

References

  1. Nogués, J. & Schuller, I. K. Exchange bias. J. Magn. Magn. Mater. 192, 203–232 (1999).

    Article  Google Scholar 

  2. Berkowitz, A. E. & Takano, K. Exchange anisotropy—a review. J. Magn. Magn. Mater. 200, 552–570 (1999).

    Article  CAS  Google Scholar 

  3. Zhang, W. & Krishnan, K. M. Epitaxial exchange-bias systems: from fundamentals to future spin-orbitronics. Mater. Sci. Eng. R. Rep. 105, 1–20 (2016).

    Article  Google Scholar 

  4. Meiklejohn, W. H. & Bean, C. P. New magnetic anisotropy. Phys. Rev. 105, 904–913 (1957).

    Article  CAS  Google Scholar 

  5. Radu, F. et al. Origin of the reduced exchange bias in an epitaxial FeNi(111)/CoO(111) bilayer. Phys. Rev. B 79, 184425 (2009).

    Article  Google Scholar 

  6. Gruyters, M. & Schmitz, D. Microscopic nature of ferro- and antiferromagnetic interface coupling of uncompensated magnetic moments in exchange bias systems. Phys. Rev. Lett. 100, 077205 (2008).

    Article  CAS  Google Scholar 

  7. Miron, I. M. et al. Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer. Nat. Mater. 9, 230–234 (2010).

    Article  Google Scholar 

  8. Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. Nature 476, 189–193 (2011).

    Article  CAS  Google Scholar 

  9. Liu, L. et al. Spin–torque switching with the giant spin Hall effect of tantalum. Science 336, 555–558 (2012).

    Article  CAS  Google Scholar 

  10. Liu, L., Lee, O. J., Gudmundsen, T. J., Ralph, D. C. & Buhrman, R. A. Current-induced switching of perpendicularly magnetized magnetic layers using spin torque from the spin hall effect. Phys. Rev. Lett. 109, 096602 (2012).

    Article  Google Scholar 

  11. Pai, C.-F. et al. Spin transfer torque devices utilizing the giant spin Hall effect of tungsten. Appl. Phys. Lett. 101, 122404 (2012).

    Article  Google Scholar 

  12. Cubukcu, M. et al. Spin–orbit torque magnetization switching of a three-terminal perpendicular magnetic tunnel junction. Appl. Phys. Lett. 104, 042406 (2014).

    Article  Google Scholar 

  13. Safeer, C. K. et al. Spin–orbit torque magnetization switching controlled by geometry. Nat. Nanotechnol. 11, 143–146 (2016).

    Article  CAS  Google Scholar 

  14. Fukami, S., Anekawa, T., Zhang, C. & Ohno, H. A spin–orbit torque switching scheme with collinear magnetic easy axis and current configuration. Nat. Nanotechnol. 11, 621–625 (2016).

    Article  CAS  Google Scholar 

  15. Qiu, X. et al. Spin–orbit-torque engineering via oxygen manipulation. Nat. Nanotechnol. 10, 333–338 (2015).

    Article  CAS  Google Scholar 

  16. Huang, K.-F., Wang, D.-S., Tsai, M.-H., Lin, H.-H. & Lai, C.-H. Initialization-free multilevel states driven by spin–orbit torque switching. Adv. Mater. 29, 1601575 (2017).

    Article  Google Scholar 

  17. Baumgartner, M. et al. Spatially and time-resolved magnetization dynamics driven by spin–orbit torques. Nat. Nanotechnol. 12, 980–986 (2017).

    Article  CAS  Google Scholar 

  18. Lee, O. J. et al. Central role of domain wall depinning for perpendicular magnetization switching driven by spin torque from the spin Hall effect. Phys. Rev. B 89, 024418 (2014).

    Article  Google Scholar 

  19. Van den Brink, A. et al. Field-free magnetization reversal by spin–Hall effect and exchange bias. Nat. Commun. 7, 10854 (2016).

    Article  Google Scholar 

  20. Rojas-Sánchez, J. C. et al. Perpendicular magnetization reversal in Pt/[Co/Ni]3/Al multilayers via the spin–Hall effect of Pt. Appl. Phys. Lett. 108, 082406 (2016).

    Article  Google Scholar 

  21. Nunez, A. S., Duine, R. A. & MacDonald, A. H. Antiferromagnetic metal spintronics. Phil. Trans. R. Soc. A 369, 3098–3114 (2011).

    Article  Google Scholar 

  22. Jungwirth, T., Marti, X., Wadley, P. & Wunderlich, J. Antiferromagnetic spintronics. Nat. Nanotechnol. 11, 231–241 (2016).

    Article  CAS  Google Scholar 

  23. He, X. et al. Robust isothermal electric control of exchange bias at room temperature. Nat. Mater. 9, 579–585 (2010).

    Article  CAS  Google Scholar 

  24. Wu, S. M. et al. Reversible electric control of exchange bias in a multiferroic field-effect device. Nat. Mater. 9, 756–761 (2010).

    Article  CAS  Google Scholar 

  25. Oh, Y. W. et al. Field-free switching of perpendicular magnetization through spin–orbit torque in antiferromagnet/ferromagnet/oxide structures. Nat. Nanotechnol. 11, 878–884 (2016).

    Article  CAS  Google Scholar 

  26. Kong, W. J. et al. Field-free spin Hall effect driven magnetization switching in Pd/Co/IrMn exchange coupling system. Appl. Phys. Lett. 109, 132402 (2016).

    Article  Google Scholar 

  27. Wu, D. et al. Spin–orbit torques in perpendicularly magnetized Ir22Mn78/Co20Fe60B20/MgO multilayer. Appl. Phys. Lett. 109, 222401 (2016).

    Article  Google Scholar 

  28. Fukami, S., Zhang, C., Duttagupta, S., Kurenkov, A. & Ohno, H. Magnetization switching by spin–orbit torque in an antiferromagnet–ferromagnet bilayer system. Nat. Mater. 15, 535–541 (2016).

    Article  CAS  Google Scholar 

  29. Du, C., Wang, H., Yang, F. & Hammel, P. C. Systematic variation of spin–orbit coupling with d-orbital filling: Large inverse spin Hall effect in 3d transition metals. Phys. Rev. B 90, 140407 (2014).

    Article  Google Scholar 

  30. Pham, T. H. et al. Thermal contribution to the spin–orbit torque in metallic–ferrimagnetic systems. Phys. Rev. Appl. 9, 064032 (2018).

    Article  Google Scholar 

  31. Zhang, W. et al. Spin Hall effects in metallic antiferromagnets. Phys. Rev. Lett. 113, 196602 (2014).

    Article  Google Scholar 

  32. Zhang, W. et al. All-electrical manipulation of magnetization dynamics in a ferromagnet by antiferromagnets with anisotropic spin Hall effects. Phys. Rev. B 92, 144405 (2015).

    Article  Google Scholar 

  33. Ghosh, A., Auffret, S., Ebels, U. & Bailey, W. E. Penetration depth of transverse spin current in ultrathin ferromagnets. Phys. Rev. Lett. 109, 127202 (2012).

    Article  CAS  Google Scholar 

  34. Zhang, J., Levy, P. M., Zhang, S. & Antropov, V. Identification of transverse spin currents in noncollinear magnetic structures. Phys. Rev. Lett. 93, 256602 (2004).

    Article  Google Scholar 

  35. Daalderop, G. H. O., Kelly, P. J. & DenBroeder, F. J. A. Prediction and confirmation of perpendicular magnetic anisotropy in Co/Ni multilayers. Phys. Rev. Lett. 68, 682–685 (1992).

    Article  CAS  Google Scholar 

  36. Kim, J. et al. Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO. Nat. Mater. 12, 240–245 (2013).

    Article  CAS  Google Scholar 

  37. Garello, K. et al. Symmetry and magnitude of spin–orbit torques in ferromagnetic heterostructures. Nat. Nanotechnol. 8, 587–593 (2013).

    Article  CAS  Google Scholar 

  38. Lee, K.-S., Lee, S.-W., Min, B.-C. & Lee, K.-J. Threshold current for switching of a perpendicular magnetic layer induced by spin Hall effect. Appl. Phys. Lett. 102, 112410 (2013).

    Article  Google Scholar 

  39. Vallobra, P. et al. Manipulating exchange bias using all-optical helicity-dependent switching. Phys. Rev. B 96, 144403 (2017).

    Article  Google Scholar 

  40. Mishra, R. et al. Anomalous current-induced spin torques in ferrimagnets near compensation. Phys. Rev. Lett. 118, 167201 (2017).

    Article  Google Scholar 

  41. Qiu, X. et al. Enhanced spin–orbit torque via modulation of spin current absorption. Phys. Rev. Lett. 117, 217206 (2016).

    Article  Google Scholar 

  42. Freitas, P. P., Ferreira, R. & Cardoso, S. Spintronic sensors. Proc. IEEE 104, 1894–1918 (2016).

    Article  Google Scholar 

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Acknowledgements

This work was partially supported by the Ministry of Science and Technology of Republic of China under Grant No. MOST 107-2218-E-007-024, MOST 106-2221-E-007-037-MY2 and MOST 106-2112-M-007-011-MY3. The authors thank Prof. Po-Tsun Liu, Prof. Ting-Chang Chang and Keithley Instruments Taiwan for the help on TRRM measurement.

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Authors and Affiliations

  1. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan

    Po-Hung Lin, Bo-Yuan Yang, Ming-Han Tsai, Po-Chuan Chen, Kuo-Feng Huang & Chih-Huang Lai

  2. Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

    Hsiu-Hau Lin

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Contributions

P.-H.L., B,-Y,Y., M.-H.T. and K.-F.H. designed the experiments and measurements. P.-H.L., B,-Y,Y., M.-H.T. and P.-C.C. made the samples. H.-H.L. and C.-H.L. constructed the explanation of phenomenon for the exchange-bias switching by SOT; P.-H.L., B.-Y. Y., M.-H.T., H.-H.L. and C.-H.L. discussed and finished the manuscript. All authors provided the suggestions on the results and revized the manuscript.

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Correspondence to Hsiu-Hau Lin or Chih-Huang Lai.

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Supplementary Information

Supplementary Figures 1–17, Supplementary Table 1, Supplementary Notes 1–12, Supplementary References 1–9

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Lin, PH., Yang, BY., Tsai, MH. et al. Manipulating exchange bias by spin–orbit torque. Nat. Mater. 18, 335–341 (2019). https://doi.org/10.1038/s41563-019-0289-4

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