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.

Charge order and three-site distortions in the Verwey structure of magnetite

Abstract

The mineral magnetite (Fe3O4) undergoes a complex structural distortion and becomes electrically insulating at temperatures less than 125 kelvin. Verwey proposed in 1939 that this transition is driven by a charge ordering of Fe2+ and Fe3+ ions1, but the ground state of the low-temperature phase has remained contentious2,3 because twinning of crystal domains hampers diffraction studies of the structure4. Recent powder diffraction refinements5,6,7 and resonant X-ray studies8,9,10,11,12 have led to proposals of a variety of charge-ordered and bond-dimerized ground-state models13,14,15,16,17,18,19. Here we report the full low-temperature superstructure of magnetite, determined by high-energy X-ray diffraction from an almost single-domain, 40-micrometre grain, and identify the emergent order. The acentric structure is described by a superposition of 168 atomic displacement waves (frozen phonon modes), all with amplitudes of less than 0.24 ångströms. Distortions of the FeO6 octahedra show that Verwey’s hypothesis is correct to a first approximation and that the charge and Fe2+ orbital order are consistent with a recent prediction17. However, anomalous shortening of some Fe–Fe distances suggests that the localized electrons are distributed over linear three-Fe-site units, which we call ‘trimerons’. The charge order and three-site distortions induce substantial off-centre atomic displacements and couple the resulting large electrical polarization to the magnetization. Trimerons may be important quasiparticles in magnetite above the Verwey transition and in other transition metal oxides.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Reciprocal lattice synchrotron X-ray diffraction intensities for magnetite microcrystal grains at 90 K.
Figure 2: The 168 displacement amplitudes of the low-temperature Cc magnetite structure.
Figure 3: Local distortion distributions that reveal electronic order in the low-temperature magnetite structure.
Figure 4: Charge, orbital and trimeron order in the low-temperature magnetite structure.

Similar content being viewed by others

References

  1. Verwey, E. J. W. Electronic conduction of magnetite (Fe3O4) and its transition point at low temperatures. Nature 144, 327–328 (1939)

    Article  ADS  CAS  Google Scholar 

  2. Walz, F. The Verwey transition: a topical review. J. Phys. Condens. Matter 14, R285–R340 (2002)

    Article  ADS  CAS  Google Scholar 

  3. Coey, M. Condensed-matter physics: charge-ordering in oxides. Nature 430, 155–157 (2004)

    Article  ADS  CAS  Google Scholar 

  4. Iizumi, M. et al. Structure of magnetite (Fe3O4) below the Verwey transition-temperature. Acta Crystallogr. B 38, 2121–2133 (1982)

    Article  Google Scholar 

  5. Wright, J. P., Attfield, J. P. & Radaelli, P. G. Long range charge ordering in magnetite below the Verwey transition. Phys. Rev. Lett. 87, 266401 (2001)

    Article  ADS  CAS  Google Scholar 

  6. Wright, J. P., Attfield, J. P. & Radaelli, P. G. Charge ordered structure of magnetite Fe3O4 below the Verwey transition. Phys. Rev. B 66, 214422 (2002)

    Article  ADS  Google Scholar 

  7. Blasco, J., Garcia, J. & Subias, G. Structural transformation in magnetite below the Verwey transition. Phys. Rev. B 83, 104105 (2011)

    Article  ADS  Google Scholar 

  8. Goff, R. J., Wright, J. P., Attfield, J. P. & Radaelli, P. G. Resonant X-ray diffraction study of the charge ordering in magnetite. J. Phys. Condens. Matter 17, 7633–7642 (2005)

    Article  ADS  CAS  Google Scholar 

  9. Nazarenko, E. et al. Resonant X-ray diffraction studies on the charge ordering in magnetite. Phys. Rev. Lett. 97, 056403 (2006)

    Article  ADS  CAS  Google Scholar 

  10. Joly, Y. et al. Low-temperature structure of magnetite studied using resonant X-ray scattering. Phys. Rev. B 78, 134110 (2008)

    Article  ADS  Google Scholar 

  11. Bland, S. R. et al. Full polarization analysis of resonant superlattice and forbidden X-ray reflections in magnetite. J. Phys. Condens. Matter 21, 485601 (2009)

    Article  CAS  Google Scholar 

  12. Lorenzo, J. E. et al. Charge and orbital correlations at and above the Verwey phase transition in magnetite. Phys. Rev. Lett. 101, 226401 (2008)

    Article  ADS  CAS  Google Scholar 

  13. Seo, H., Ogata, M. & Fukuyama, H. Aspects of the Verwey transition in magnetite. Phys. Rev. B 65, 085107 (2002)

    Article  ADS  Google Scholar 

  14. Jeng, H. T., Guo, G. Y. & Huang, D. J. Charge-orbital ordering and Verwey transition in magnetite. Phys. Rev. Lett. 93, 156403 (2004)

    Article  ADS  Google Scholar 

  15. Jeng, H. T., Guo, G. Y. & Huang, D. J. Charge-orbital ordering in low-temperature structures of magnetite: GGA+U investigations. Phys. Rev. B 74, 195115 (2006)

    Article  ADS  Google Scholar 

  16. van den Brink, J. & Khomskii, D. I. Multiferroicity due to charge ordering. J. Phys. Condens. Matter 20, 434217 (2008)

    Article  Google Scholar 

  17. Yamauchi, K., Fukushima, T. & Picozzi, S. Ferroelectricity in multiferroic magnetite Fe3O4 driven by noncentrosymmetric Fe2+/Fe3+ charge-ordering: first-principles study. Phys. Rev. B 79, 212404 (2009)

    Article  ADS  Google Scholar 

  18. Zhou, F. & Ceder, G. First-principles determination of charge and orbital interactions in Fe3O4 . Phys. Rev. B 81, 205113 (2010)

    Article  ADS  Google Scholar 

  19. Fukushima, T., Yamauchi, K. & Picozzi, S. Ab initio investigations of Fe2+/Fe3+ bond dimerization and ferroelectricity induced by intermediate site/bond-centered charge ordering in magnetite. J. Phys. Soc. Jpn 80, 014709 (2011)

    Article  ADS  Google Scholar 

  20. Yoshida, J. & Iida, S. X-ray-diffraction study on low-temperature phase of magnetite. J. Phys. Soc. Jpn. 42, 230–237 (1977)

    Article  ADS  Google Scholar 

  21. Kasama, T., Church, N. S., Feinberg, J. M., Dunin-Borkowski, R. E. & Harrison, R. J. Direct observation of ferrimagnetic/ferroelastic domain interactions in magnetite below the Verwey transition. Earth Planet. Sci. Lett. 297, 10–17 (2010)

    Article  ADS  CAS  Google Scholar 

  22. Attfield, J. P. Charge ordering in transition metal oxides. Solid State Sci. 8, 861–867 (2006)

    Article  ADS  CAS  Google Scholar 

  23. Verwey, E. J. W. & Heilmann, E. L. Physical properties and cation arrangement of oxides with spinel structures. 1. Cation arrangement in spinels. J. Chem. Phys. 15, 174–180 (1947)

    Article  ADS  CAS  Google Scholar 

  24. Anderson, P. W. Ordering and antiferromagnetism in ferrites. Phys. Rev. 102, 1008–1013 (1956)

    Article  ADS  CAS  Google Scholar 

  25. Downward, L. et al. Universal relationship between magnetization and changes in the local structure of La1-xCaxMnO3: evidence for magnetic dimers. Phys. Rev. Lett. 95, 106401 (2005)

    Article  ADS  CAS  Google Scholar 

  26. Yang, M. H. et al. Anion order in perovskite oxynitrides. Nat. Chem. 3, 47–52 (2011)

    Article  CAS  Google Scholar 

  27. Ikeda, N. et al. Ferroelectricity from iron valence ordering in the charge-frustrated system LuFe2O4 . Nature 436, 1136–1138 (2005)

    Article  ADS  CAS  Google Scholar 

  28. Yamada, Y., Wakabayashi, N. & Nicklow, R. M. Neutron diffuse-scattering in magnetite due to molecular polarons. Phys. Rev. B 21, 4642–4648 (1980)

    Article  ADS  CAS  Google Scholar 

  29. Shepherd, J. P., Koenitzer, J. W., Aragon, R., Sandberg, C. J. & Honig, J. M. Heat-capacity studies on single-crystal annealed Fe3O4 . Phys. Rev. B 31, 1107–1113 (1985)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We thank C. Morrison for supplying code for electrical polarization calculations, J. Honig for provision of the magnetite sample, the Leverhulme Trust for financial support, and EPSRC and STFC for financial support and provision of continuing access to ESRF.

Author information

Authors and Affiliations

Authors

Contributions

J.P.A. and J.P.W. designed the study, data were collected and analysed by M.S.S. and J.P.W., and J.P.A. wrote the paper with contributions from M.S.S. and J.P.W.

Corresponding authors

Correspondence to Jon P. Wright or J. Paul Attfield.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Methods, Supplementary Figures 1-3 with legends, Supplementary Tables 1-7 and additional references. (PDF 960 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Senn, M., Wright, J. & Attfield, J. Charge order and three-site distortions in the Verwey structure of magnetite. Nature 481, 173–176 (2012). https://doi.org/10.1038/nature10704

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature10704

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

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