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Substantial reduction of critical current for magnetization switching in an exchange-biased spin valve

Nature Materials volume 3, pages 361–364 (2004)Cite this article

A Corrigendum to this article was published on 01 April 2005

Abstract

Great interest1,2,3,4,5,6,7,8,9,10 in current-induced magnetic excitation and switching in a magnetic nanopillar has been caused by the theoretical predictions11,12 of these phenomena. The concept of using a spin-polarized current to switch the magnetization orientation of a magnetic layer provides a possible way to realize future 'current-driven' devices13: in such devices, direct switching of the magnetic memory bits would be produced by a local current application, instead of by a magnetic field generated by attached wires. Until now, all the reported work on current-induced magnetization switching has been concentrated on a simple ferromagnet/Cu/ferromagnet trilayer. Here we report the observation of current-induced magnetization switching in exchange-biased spin valves (ESPVs) at room temperature. The ESPVs clearly show current-induced magnetization switching behaviour under a sweeping direct current with a very high density. We show that insertion of a ruthenium layer between an ESPV nanopillar and the top electrode effectively decreases the critical current density from about 108 to 107 A cm−2. In a well-designed 'antisymmetric' ESPV structure, this critical current density can be further reduced to 2 × 106 A cm−2. We believe that the substantial reduction of critical current could make it possible for current-induced magnetization switching to be directly applied in spintronic devices, such as magnetic random-access memory.

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Figure 1: Curves of resistance (R) as a function of a sweeping d.c. current (I) for the two nanopillars with different structures.
Figure 2: CPP-GMR loop for one nanopillar with structure III.
Figure 3: Magnetic-field dependence of the critical current (Icrit) for CIMS.
Figure 4: Microscopic views of the fabricated CPP-ESPV nanopillar.

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References

  1. Stiles, M.D. & Zangwill, A. Anatomy of spin-transfer torque. Phys. Rev. B 66, 014407 (2002).

    Article  Google Scholar 

  2. Zhang, S., Levy, P.M. & Fert, A. Mechanisms of spin-polarized current-driven magnetization switching. Phys. Rev. Lett. 88, 236601 (2002).

    Article  CAS  Google Scholar 

  3. Myers, E.B., Ralph, D.C., Katine, J.A., Louie, R.N. & Buhrman, R.A. Current-induced switching of domains in magnetic multilayer devices. Science 285, 867–870 (1999).

    Article  CAS  Google Scholar 

  4. Tsoi, M. et al. Generation and detection of phase-coherent current-driven magnons in magnetic multilayers. Nature 406, 46–48 (2000).

    Article  CAS  Google Scholar 

  5. Katine, J.A., Albert, F.J., Buhrman, R.A., Myers, E.B. & Ralph, D.C. Current-driven magnetization reversal and spin-wave excitation in Co/Cu/Co pillars. Phys. Rev. Lett. 84, 3149–3152 (2000).

    Article  CAS  Google Scholar 

  6. Bussmann, K., Prinz, G.A., Cheng, S.-F. & Wang, D. Switching of vertical giant magnetoresistance devices by current through the device. Appl. Phys. Lett. 75, 2476–2478 (1999).

    Article  CAS  Google Scholar 

  7. Yaowen, L., Zongzhi, Z., Freitas, P.P. & Martins, J.L. Current-induced magnetization switching in magnetic tunnel junctions. Appl. Phys. Lett. 82, 2871–2873 (2003).

    Article  Google Scholar 

  8. Mancoff, F.B. et al. Angular dependence of spin-transfer switching in a magnetic nanostructure. Appl. Phys. Lett. 83, 1596–1598 (2003).

    Article  CAS  Google Scholar 

  9. Urazhdin, S., Birge, N.O., Pratt, W.P. Jr & Bass, J. Switching current versus magnetoresistance in magnetic multilayer nanopillars. Appl. Phys. Lett. 84, 1516–1518 (2004).

    Article  CAS  Google Scholar 

  10. Wegrowe, J.-E. et al. Exchange torque and spin transfer between spin polarized current and ferromagnetic layers. Appl. Phys. Lett. 80, 3775–3777 (2002).

    Article  CAS  Google Scholar 

  11. Slonczewski, J.C. Current-driven excitation of magnetic multilayers. J. Magn. Magn. Mater. 159, L1–L9 (1996).

    Article  CAS  Google Scholar 

  12. Berger, L. Emission of spin waves by a magnetic multilayer traversed by a current. Phys. Rev. B 54, 9353–9358 (1996).

    Article  CAS  Google Scholar 

  13. Inomata, K. Present and future of magnetic RAM technology. IEICE Trans. Electron E84-C, 740–746 (2001).

    Google Scholar 

  14. Nakasaka, K., Seyama, Y., Varga, L., Shimizu, Y. & Tanaka, A. Giant magnetoresistance properties of specular spin valve films in a current perpendicular to plane structure. J. Appl. Phys. 89, 6943–6945 (2002).

    Article  Google Scholar 

  15. Yuasa, H. et al. Output enhancement of spin-valve giant magnetoresistance in current-perpendicular-to-plane geometry. J. Appl. Phys. 92, 2646–2650 (2002).

    Article  CAS  Google Scholar 

  16. Campbell, I.A. & Fert, A. in Ferromagnetic Materials Vol. 3, Ch. 9 (ed. Wolforth, E. P.) 751 (North-Holland, Amsterdam, 1982).

    Google Scholar 

  17. Jiang, Y., Abe, S., Nozaki, T., Tezuka, N. & Inomata, K. Perpendicular giant magnetoresistance and magnetic switching properties of a single spin valve with a synthetic antiferromagnet as a free layer. Phys. Rev. B 68, 224426 (2003).

    Article  Google Scholar 

  18. Berger, L. Multilayer configuration for experiments of spin precession induced by a dc current. J. Appl. Phys. 93, 7693–7695 (2003).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the IT program of Research Revolution 2002 (RR 2002), the Priority Area (15206074 to 1407602 from MEXT), a NEDO grant for NAME, and SCAT, Hoso-bunka foundation.

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Authors and Affiliations

  1. Department of Materials Science, Graduate School of Engineering, Tohoku University, and CREST, Japan Science and Technology Agency, Sendai, 980-8579, Japan

    Y. Jiang, T. Nozaki, S. Abe, T. Ochiai, A. Hirohata, N. Tezuka & K. Inomata

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Correspondence to Y. Jiang.

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Jiang, Y., Nozaki, T., Abe, S. et al. Substantial reduction of critical current for magnetization switching in an exchange-biased spin valve. Nature Mater 3, 361–364 (2004). https://doi.org/10.1038/nmat1120

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