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:

Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography

Nature Nanotechnology volume 9, pages 337–342 (2014)Cite this article

Subjects

Abstract

Skyrmions are nanoscale spin textures that are viewed as promising candidates as information carriers in future spintronic devices1,2,3. Skyrmions have been observed using neutron scattering4,5 and microscopy techniques6,7,8,9,10,11. Real-space imaging using electrons is a straightforward way to interpret spin configurations by detecting the phase shifts due to electromagnetic fields. Here, we report the first observation by electron holography of the magnetic flux and the three-dimensional spin configuration of a skyrmion lattice in Fe0.5Co0.5Si thin samples. The magnetic flux inside and outside a skyrmion was directly visualized and the handedness of the magnetic flux flow was found to be dependent on the direction of the applied magnetic field. The electron phase shifts φ in the helical and skyrmion phases were determined using samples with a stepped thickness t (from 55 nm to 510 nm), revealing a linear relationship (φ = 0.00173t). The phase measurements were used to estimate the three-dimensional structures of both the helical and skyrmion phases, demonstrating that electron holography is a useful tool for studying complex magnetic structures and for three-dimensional, real-space mapping of magnetic fields12.

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: Lorentz micrographs of an Fe0.5Co0.5Si thin sample.
Figure 2: Phase maps showing the skyrmion lattice and paramagnetic state.
Figure 3: Magnetic flux maps of the skyrmion lattice.
Figure 4: Handedness reversal of magnetic flux flow with change in direction of the applied field.
Figure 5: Three-dimensional structures of skyrmions.

Similar content being viewed by others

References

  1. Fert, A., Cros, V. & Sampaio, J. Skyrmions on the track. Nature Nanotech. 8, 152–156 (2013).

    Article  CAS  Google Scholar 

  2. Iwasaki, J., Mochizuki, M. & Nagaosa, N. Universal current–velocity relation of skyrmion motion in chiral magnets. Nature Commun. 4, 1463 (2013).

    Article  Google Scholar 

  3. Rosch, A. Skyrmions: moving with the currents. Nature Nanotech. 8, 160–161 (2013).

    Article  CAS  Google Scholar 

  4. Pfleiderer, C. et al. Partial order in the non-Fermi-liquid phase of MnSi. Nature 427, 227–231 (2004).

    Article  CAS  Google Scholar 

  5. Muhlbauer, S. et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).

    Article  CAS  Google Scholar 

  6. Yu, X. Z. et al. Real-space observation of a two-dimensional skyrmion crystal. Nature 465, 901–904 (2010).

    Article  CAS  Google Scholar 

  7. Yu, X. Z. et al. Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe. Nature Mater. 10, 106–109 (2011).

    Article  CAS  Google Scholar 

  8. Tonomura, A. et al. Real-space observation of skyrmion lattice in helimagnet MnSi thin samples. Nano Lett. 12, 1673–1677 (2012).

    Article  CAS  Google Scholar 

  9. Heinze, S. et al. Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions. Nature Phys. 7, 713–718 (2011).

    Article  CAS  Google Scholar 

  10. Milde, P. et al. Unwinding of a skyrmion lattice by magnetic monopoles. Science 340, 1076–1080 (2013).

    Article  CAS  Google Scholar 

  11. Romming, N. et al. Writing and deleting single magnetic skyrmions. Science 341, 636–639 (2013).

    Article  CAS  Google Scholar 

  12. Nagaosa, N., Yu, X. Z. & Tokura, Y. Gauge fields in real and momentum spaces in magnets: monopoles and skyrmions. Phil. Trans. R. Soc. A 370, 5806–5819 (2012).

    Article  CAS  Google Scholar 

  13. Jonietz, F. et al. Spin transfer torques in MnSi at ultralow current densities. Science 330, 1648–1651 (2010).

    Article  CAS  Google Scholar 

  14. Yu, X. Z. et al. Skyrmion flow near room temperature in an ultralow current density. Nature Commun. 3, 1–6 (2012).

    CAS  Google Scholar 

  15. Lee, M., Kang, W., Onose, Y., Tokura, Y. & Ong, N. P. Unusual Hall effect anomaly in MnSi under pressure. Phys. Rev. Lett. 102, 186601 (2009).

    Article  Google Scholar 

  16. Neubauer, A. et al. Topological Hall effect in the A phase of MnSi. Phys. Rev. Lett. 102, 186602 (2009).

    Article  CAS  Google Scholar 

  17. Binz, B. & Vishwanath, A. Theory of helical spin crystals: phases, textures, and properties. Phys. Rev. B 74, 214408 (2006).

    Article  Google Scholar 

  18. Park, J. H. & Han, J. H. Zero-temperature phases for chiral magnets in three dimensions. Phys. Rev. B 83, 184406 (2011).

    Article  Google Scholar 

  19. Kanazawa, N. et al. Possible skyrmion-lattice ground state in the B20 chiral-lattice magnet MnGe as seen via small-angle neutron scattering. Phys. Rev. B 86, 134425 (2012).

    Article  Google Scholar 

  20. Seki, S., Yu, X. Z., Ishiwata, S. & Tokura, Y. Observation of skyrmions in a multiferroic material. Science 336, 198–201 (2012).

    Article  CAS  Google Scholar 

  21. Tonomura, A. et al. Motion of vortices in superconductors. Nature 397, 308–309 (1999).

    Article  CAS  Google Scholar 

  22. Park, H. S. et al. Direct observation of magnetization reversal in thin Nd2Fe14B film. J. Appl. Phys. 97, 033908 (2005).

    Article  Google Scholar 

  23. Junginger, F. et al. Spin torque and heating effects in current-induced domain wall motion probed by transmission electron microscopy. Appl. Phys. Lett. 90, 132506 (2007).

    Article  Google Scholar 

  24. Park, H. S., Baskin, J. S. & Zewail, A. H. 4D Lorentz electron microscopy imaging: magnetic domain wall nucleation, reversal, and wave velocity. Nano Lett. 10, 3796–3803 (2010).

    Article  CAS  Google Scholar 

  25. Tonomura, A. Electron Holography 2nd edn (Springer-Verlag, 1999).

    Book  Google Scholar 

  26. Cowley, J. M. & Spence, J. C. H. Principles and Theory of Electron Holography, Introduction to Electron Holography (eds Volkl, E., Allard, L. F. & Joy, D. C.) (Kluwer Academic/Plenum, 1998).

    Google Scholar 

  27. Park, H. S. et al. Nanoscale magnetic characterization of tunneling magnetoresistance spin valve head by electron holography. Small 8, 3640–3646 (2012).

    Article  CAS  Google Scholar 

  28. Shibata, K. et al. Towards control of the size and helicity of skyrmions in helimagnetic alloys by spin–orbit coupling. Nature Nanotech. 8, 723–728 (2013).

    Article  CAS  Google Scholar 

  29. Nagaosa, N. & Tokura, Y. Topological properties and dynamics of magnetic skyrmions, Nature Nanotech. 8, 899–911 (2013).

    Article  CAS  Google Scholar 

  30. Harada, K., Endo, J., Osakabe, N. & Tonomura, A. Direction-free magnetic field application system. J. Surf. Sci. Nanotech. 6, 29–34 (2008).

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank Y.A. Ono for critical reading of the manuscript. This research was supported by a grant from the Japan Society for the Promotion of Science (JSPS) through the ‘Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program)’, initiated by the Council for Science and Technology Policy (CSTP) under the programmes ‘Development and Application of an Atomic-resolution Holography Electron Microscope’ and ‘Quantum Science on Strong Correlation’.

Author information

Author notes

  1. Hyun Soon Park

    Present address: Present address: Department of Materials Science and Engineering, Dong-A University, Saha-gu, Busan 604-714, Republic of Korea,

  2. Akira Tonomura: Deceased

Authors and Affiliations

  1. RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan

    Hyun Soon Park, Xiuzhen Yu, Shinji Aizawa, Toshiaki Tanigaki, Daisuke Shindo & Yoshinori Tokura

  2. Central Research Laboratory, Hitachi Ltd, 2520 Akanuma, Hatoyama-machi, Hiki-gun, Hatoyama, Saitama, 350-0395, Japan

    Tetsuya Akashi, Yoshio Takahashi & Akira Tonomura

  3. Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi-shi, Saitama, 332-0012, Japan

    Tsuyoshi Matsuda

  4. Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan

    Naoya Kanazawa & Yoshinori Tokura

  5. Department of Basic Science, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan

    Yoshinori Onose

  6. Interdisciplinary Materials Research for Advanced Materials, Tohoku University, 1-1-2-chome, Katahira, Aoba-ku, Sendai, 332-0012, Japan

    Daisuke Shindo

Authors
  1. Hyun Soon Park
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Xiuzhen Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Shinji Aizawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Toshiaki Tanigaki
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Tetsuya Akashi
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Yoshio Takahashi
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Tsuyoshi Matsuda
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Naoya Kanazawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Yoshinori Onose
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Daisuke Shindo
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Akira Tonomura
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Yoshinori Tokura
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

H.S.P., A.T. and Y.T. conceived and designed the experiments. H.S.P., S.A., T.T., T.A. and T.M. performed the experiments and analysed the data. N.K. and Y.O. contributed to the synthesis of samples. H.S.P. and Y.T. wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Hyun Soon Park.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Park, H., Yu, X., Aizawa, S. et al. Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography. Nature Nanotech 9, 337–342 (2014). https://doi.org/10.1038/nnano.2014.52

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2014.52

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