Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Magneto-ionic control of interfacial magnetism

Nature Materials volume 14, pages 174–181 (2015)Cite this article

Subjects

Abstract

In metal/oxide heterostructures, rich chemical1,2, electronic3,4,5, magnetic6,7,8,9 and mechanical10,11 properties can emerge from interfacial chemistry and structure. The possibility to dynamically control interface characteristics with an electric field paves the way towards voltage control of these properties in solid-state devices. Here, we show that electrical switching of the interfacial oxidation state allows for voltage control of magnetic properties to an extent never before achieved through conventional magneto-electric coupling mechanisms. We directly observe in situ voltage-driven O2− migration in a Co/metal-oxide bilayer, which we use to toggle the interfacial magnetic anisotropy energy by >0.75 erg cm−2 at just 2 V. We exploit the thermally activated nature of ion migration to markedly increase the switching efficiency and to demonstrate reversible patterning of magnetic properties through local activation of ionic migration. These results suggest a path towards voltage-programmable materials based on solid-state switching of interface oxygen chemistry.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Cross-sectional TEM and EELS analysis.
Figure 2: Device schematics and voltage control of magnetic anisotropy.
Figure 3: Voltage-induced propagation of oxidation front.
Figure 4: Fast anisotropy switching by engineering electrode and oxide.
Figure 5: Effects of voltage and laser illumination on magnetic anisotropy.
Figure 6: Laser-defined anisotropy patterns and DW conduits.

Similar content being viewed by others

References

  1. Stair, P. C. Metal-oxide interfaces where the action is. Nature Chem. 3, 345–346 (2011).

    Article  CAS  Google Scholar 

  2. Yamada, Y. et al. Nanocrystal bilayer for tandem catalysis. Nature Chem. 3, 372–376 (2011).

    Article  CAS  Google Scholar 

  3. Yang, J. J., Strukov, D. B. & Stewart, D. R. Memristive devices for computing. Nature Nanotech. 8, 13–24 (2013).

    Article  CAS  Google Scholar 

  4. Waser, R., Dittmann, R., Staikov, G. & Szot, K. Redox-based resistive switching memories—nanoionic mechanisms, prospects, and challenges. Adv. Mater. 21, 2632–2663 (2009).

    Article  CAS  Google Scholar 

  5. Jeong, J. et al. Suppression of metal–insulator transition in VO2 by electric field-induced oxygen vacancy formation. Science 339, 1402–1405 (2013).

    Article  CAS  Google Scholar 

  6. Ikeda, S. et al. A perpendicular-anisotropy CoFeB–MgO magnetic tunnel junction. Nature Mater. 9, 721–724 (2010).

    Article  CAS  Google Scholar 

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

    Article  Google Scholar 

  8. Manchon, A. et al. X-ray analysis of the magnetic influence of oxygen in Pt/Co/AlOx trilayers. J. Appl. Phys. 103, 07A912 (2008).

    Article  Google Scholar 

  9. Rodmacq, B., Manchon, A., Ducruet, C., Auffret, S. & Dieny, B. Influence of thermal annealing on the perpendicular magnetic anisotropy of Pt/Co/AlOx trilayers. Phys. Rev. B 79, 024423 (2009).

    Article  Google Scholar 

  10. Zhang, W. & Smith, J. R. Nonstoichiometric interfaces and Al2O3 adhesion with Al and Ag. Phys. Rev. Lett. 85, 3225–3228 (2000).

    Article  CAS  Google Scholar 

  11. Howe, J. M. Bonding, structure, and properties of metal-ceramic interfaces .1. Chemical bonding, chemical-reaction, and interfacial structure. Int. Mater. Rev. 38, 233–256 (1993).

    Article  CAS  Google Scholar 

  12. Padture, N. P., Gell, M. & Jordan, E. H. Thermal barrier coatings for gas-turbine engine applications. Science 296, 280–284 (2002).

    Article  CAS  Google Scholar 

  13. Losego, M. D., Grady, M. E., Sottos, N. R., Cahill, D. G. & Braun, P. V. Effects of chemical bonding on heat transport across interfaces. Nature Mater. 11, 502–506 (2012).

    Article  CAS  Google Scholar 

  14. Maier, J. Nanoionics: Ion transport and electrochemical storage in confined systems. Nature Mater. 4, 805–815 (2005).

    Article  CAS  Google Scholar 

  15. Adler, S. B. Factors governing oxygen reduction in solid oxide fuel cell cathodes. Chem. Rev. 104, 4791–4843 (2004).

    Article  CAS  Google Scholar 

  16. Maruyama, T. et al. Large voltage-induced magnetic anisotropy change in a few atomic layers of iron. Nature Nanotech. 4, 158–161 (2009).

    Article  CAS  Google Scholar 

  17. Wang, W. G., Li, M. G., Hageman, S. & Chien, C. L. Electric-field-assisted switching in magnetic tunnel junctions. Nature Mater. 11, 64–68 (2012).

    Article  CAS  Google Scholar 

  18. Shiota, Y. et al. Induction of coherent magnetization switching in a few atomic layers of FeCo using voltage pulses. Nature Mater. 11, 39–43 (2012).

    Article  CAS  Google Scholar 

  19. Duan, C. G. et al. Surface magnetoelectric effect in ferromagnetic metal films. Phys. Rev. Lett. 101, 137201 (2008).

    Article  Google Scholar 

  20. Bauer, U., Przybylski, M., Kirschner, J. & Beach, G. S. D. Magnetoelectric charge trap memory. Nano Lett. 12, 1437–1442 (2012).

    Article  CAS  Google Scholar 

  21. Rajanikanth, A., Hauet, T., Montaigne, F., Mangin, S. & Andrieu, S. Magnetic anisotropy modified by electric field in V/Fe/MgO(001)/Fe epitaxial magnetic tunnel junction. Appl. Phys. Lett. 103, 062402 (2013).

    Article  Google Scholar 

  22. Bauer, U., Emori, S. & Beach, G. S. D. Electric field control of domain wall propagation in Pt/Co/GdOx films. Appl. Phys. Lett. 100, 192408 (2012).

    Article  Google Scholar 

  23. Bauer, U., Emori, S. & Beach, G. S. D. Voltage-controlled domain wall traps in ferromagnetic nanowires. Nature Nanotech. 8, 411–416 (2013).

    Article  CAS  Google Scholar 

  24. Bonell, F. et al. Reversible change in the oxidation state and magnetic circular dichroism of Fe driven by an electric field at the FeCo/MgO interface. Appl. Phys. Lett. 102, 152401 (2013).

    Article  Google Scholar 

  25. Tournerie, N., Engelhardt, A. P., Maroun, F. & Allongue, P. Influence of the surface chemistry on the electric-field control of the magnetization of ultrathin films. Phys. Rev. B 86, 104434 (2012).

    Article  Google Scholar 

  26. Reichel, L., Oswald, S., Fahler, S., Schultz, L. & Leistner, K. Electrochemically driven variation of magnetic properties in ultrathin CoPt films. J. Appl. Phys. 113, 143904 (2013).

    Article  Google Scholar 

  27. Bauer, U., Emori, S. & Beach, G. S. D. Voltage-gated modulation of domain wall creep dynamics in an ultrathin metallic ferromagnet. Appl. Phys. Lett. 101, 172403 (2012).

    Article  Google Scholar 

  28. Balluffi, R. W., Allen, S. M. & Carter, W. C. Kinetics of Materials 209–228 (John Wiley, 2005).

    Book  Google Scholar 

  29. Lacour, D. et al. Magnetic properties of postoxidized Pt/Co/Al layers with perpendicular anisotropy. Appl. Phys. Lett. 90, 192506 (2007).

    Article  Google Scholar 

  30. Dahmane, Y. et al. Oscillatory behavior of perpendicular magnetic anisotropy in Pt/Co/Al(O-x) films as a function of Al thickness. Appl. Phys. Lett. 95, 222514 (2009).

    Article  Google Scholar 

  31. Strukov, D. B. & Williams, R. S. Exponential ionic drift: Fast switching and low volatility of thin-film memristors. Appl. Phys. A 94, 515–519 (2009).

    Article  CAS  Google Scholar 

  32. Chappert, C. et al. Planar patterned magnetic media obtained by ion irradiation. Science 280, 1919–1922 (1998).

    Article  CAS  Google Scholar 

  33. Franken, J. H., Swagten, H. J. M. & Koopmans, B. Shift registers based on magnetic domain wall ratchets with perpendicular anisotropy. Nature Nanotech. 7, 499–503 (2012).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Science Foundation under NSF-ECCS -1128439 and through the MRSEC Program under DMR-0819762, and by the Samsung Global MRAM Innovation program. Technical support from D. Bono, M. Tarkanian and E. Shaw is gratefully acknowledged. Work was performed using instruments in the MIT Nanostructures Laboratory, the Scanning Electron-Beam Lithography facility at the Research Laboratory of Electronics, and the Center for Materials Science and Engineering at MIT. In situ TEM and EELS characterization was conducted using the facilities of the Aalto University Nanomicroscopy Center (Aalto-NMC) in Finland.

Author information

Authors and Affiliations

  1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA

    Uwe Bauer, Aik Jun Tan, Parnika Agrawal, Satoru Emori, Harry L. Tuller & Geoffrey S. D. Beach

  2. Department of Applied Physics, NanoSpin, Aalto University School of Science, PO Box 15100, FI-00076 Aalto, Finland

    Lide Yao & Sebastiaan van Dijken

Authors
  1. Uwe Bauer
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Lide Yao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Aik Jun Tan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Parnika Agrawal
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Satoru Emori
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Harry L. Tuller
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Sebastiaan van Dijken
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Geoffrey S. D. Beach
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

U.B. and G.S.D.B. conceived and designed the experiments. H.L.T. proposed the extension of studies to higher temperatures. U.B. prepared the samples with help from A.J.T. and S.E. U.B. performed the MOKE experiments and analysed the data. P.A. and U.B. conducted the VSM and AFM measurements. S.v.D. and L.Y. performed and analysed the TEM and EELS measurements. U.B. wrote the manuscript with assistance from G.S.D.B. and input from S.v.D. and L.Y. All authors discussed the results.

Corresponding author

Correspondence to Geoffrey S. D. Beach.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 2643 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bauer, U., Yao, L., Tan, A. et al. Magneto-ionic control of interfacial magnetism. Nature Mater 14, 174–181 (2015). https://doi.org/10.1038/nmat4134

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat4134

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing