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.

  • Brief Communication
  • Published:

Materials science

The hardest known oxide

Nature volume 410, pages 653–654 (2001)Cite this article

Abstract

A material as hard as diamond or cubic boron nitride has yet to be identified1,2,3,4,5,6, but here we report the discovery of a cotunnite-structured titanium oxide which represents the hardest oxide known. This is a new polymorph of titanium dioxide, where titanium is nine-coordinated to oxygen in the cotunnite (PbCl2) structure. The phase is synthesized at pressures above 60 gigapascals (GPa) and temperatures above 1,000 K and is one of the least compressible and hardest polycrystalline materials to be described.

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: Example of profile-fitted X-ray diffraction data obtained from a cotunnite-structured TiO2 sample (space group Pnma, Z = 4, a = 5.163(2) Å, b = 2.989(1) Å, c = 5.966(2) Å, Ti (0.264(1); 0.25; 0.110(1)), O1 (0.346(1); 0.25; 0.422(1)), O2 (0.012(2); 0.75; 0.325(1)); numbers in parentheses, s.d.).

Similar content being viewed by others

References

  1. Cohen, M. L. Solid State Commun. 92, 45–52 (1994).

    Article  ADS  CAS  Google Scholar 

  2. Riedel, R. Adv. Mater. 6, 549–556 (1994).

    Article  CAS  Google Scholar 

  3. Sung, C. M. & Sung, M. Mater. Chem. Phys. 43, 1–6 (1996).

    Article  ADS  CAS  Google Scholar 

  4. Léger, J. M., Haines, J. & Blanzat, B. J. Mater. Sci. Lett. 13, 1688–1692 (1994).

    Article  Google Scholar 

  5. Lundin, U. et al. Phys. Rev. B 57, 4979–4982 (1998).

    Article  ADS  CAS  Google Scholar 

  6. Desgreniers, S. & Lagarec, K. Phys. Rev. B 59, 8467–8472 (1999).

    Article  ADS  CAS  Google Scholar 

  7. Léger, J. M. Nature 383, 401 (1996).

    Article  ADS  Google Scholar 

  8. Teter, D. M. Mater. Res. Sci. Bull. 22–27 (1998).

  9. Jhi, S. H. et al. Nature 399, 132–134 (1999).

    Article  ADS  CAS  Google Scholar 

  10. Haines, J. & Léger, J. M. Physica B 192, 232–239 (1993).

    Article  ADS  Google Scholar 

  11. Olsen, J. S., Gerward, L. & Jiang, J. Z. J. Phys. Chem. Solids 60, 229–233 (1999).

    Article  ADS  CAS  Google Scholar 

  12. Larson, A. C. & Von Dreele, R. B. Los Alamos National Laboratory, LAUR, 86 (1994).

  13. Leinenweber, K., Schuelke, U., Ekundit, S. & McMillan, P. F. in Properties of Earth and Planetary Materials at High Pressure and Temperature (eds Manghnani, M. H. & Yagi, T.) 101, 97–105 (Am. Geophys.Union, Geophys. Monogr., Washington, 1998).

    Book  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institute of Earth Sciences, Uppsala University, Uppsala, S-752 36, Sweden

    L. S. Dubrovinsky & N. A. Dubrovinskaia

  2. CSIRO Minerals, Box 312, Clayton South, 3169, Victoria, Australia

    V. Swamy & J. Muscat

  3. CCLRC Daresbury Laboratory, Daresbury, WA4 4AD, Warrington

    N. M. Harrison

  4. Department of Chemistry, Imperial College London, London, SW7 2AY, UK

    N. M. Harrison

  5. Department of Physics, Condensed Matter Theory Group, Uppsala University, S-751 21 Uppsala, Sweden

    R. Ahuja, B. Holm & B. Johansson

  6. Department of Materials Science and Engineering, Applied Materials Physics, Royal Institute of Technology, Brinellvägen 23, Stockholm, SE-100 44, Sweden

    B. Johansson

Authors
  1. L. S. Dubrovinsky
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. N. A. Dubrovinskaia
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. V. Swamy
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. J. Muscat
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. N. M. Harrison
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. R. Ahuja
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. B. Holm
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. B. Johansson
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to L. S. Dubrovinsky.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Dubrovinsky, L., Dubrovinskaia, N., Swamy, V. et al. The hardest known oxide. Nature 410, 653–654 (2001). https://doi.org/10.1038/35070650

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1038/35070650

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

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