Doping-induced disappearance of ice II from water’s phase diagram


Water and the many phases of ice display a plethora of complex physical properties and phase relationships1,2,3,4 that are of paramount importance in a range of settings including processes in Earth’s hydrosphere, the geology of icy moons, industry and even the evolution of life. Well-known examples include the unusual behaviour of supercooled water2, the emergent ferroelectric ordering in ice films4 and the fact that the ‘ordinary’ ice Ih floats on water. We report the intriguing observation that ice II, one of the high-pressure phases of ice, disappears in a selective fashion from water’s phase diagram following the addition of small amounts of ammonium fluoride. This finding exposes the strict topologically constrained nature of the ice II hydrogen-bond network, which is not found for the competing phases. In analogy to the behaviour of frustrated magnets5, the presence of the exceptional ice II is argued to have a wider impact on water’s phase diagram, potentially explaining its general tendency to display anomalous behaviour. Furthermore, the impurity-induced disappearance of ice II raises the prospect that specific dopants may not only be able to suppress certain phases but also induce the formation of new phases of ice in future studies.

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Fig. 1: Tiny amounts of ammonium fluoride (NH4F) cause ice II to disappear from water’s phase diagram.
Fig. 2: Phase transitions of D2O ice containing deuterated ammonium fluoride (ND4F) at a pressure of 0.300 GPa.
Fig. 3: Topological and thermodynamic principles by which ice II becomes unstable in the presence of NH4F.

Change history

  • 11 April 2018

    In the version of this Letter originally published, the citation to ref. 30 in the Fig. 1 caption should have been to ref. 29, and the citation to ref. 29 in the Methods should have been to ref. 30.


  1. 1.

    Canton, J. Experiments and observations on the compressibility of water and some other fluids. Phil. Trans. 54, 261–262 (1764).

    Article  Google Scholar 

  2. 2.

    Gallo, P. et al. Water: a tale of two liquids. Chem. Rev. 116, 7463–7500 (2016).

    Article  Google Scholar 

  3. 3.

    Salzmann, C. G., Radaelli, P. G., Slater, B. & Finney, J. L. The polymorphism of ice: five unresolved questions. Phys. Chem. Chem. Phys. 13, 18468–18480 (2011).

    Article  Google Scholar 

  4. 4.

    Sugimoto, T., Aiga, N., Otsuki, Y., Watanabe, K. & Matsumoto, Y. Emergent high-T c ferroelectric ordering of strongly correlated and frustrated protons in a heteroepitaxial ice film. Nat. Phys. 12, 1063–1068 (2016).

    Article  Google Scholar 

  5. 5.

    Ramirez, A. P. Strongly geometrically frustrated magnets. Annu. Rev. Mater. Sci. 24, 453–480 (1994).

    ADS  Article  Google Scholar 

  6. 6.

    Petrenko, V. F. & Whitworth, R. W. Physics of Ice (Oxford Univ. Press, Oxford, 1999).

  7. 7.

    Salzmann, C. G., Radaelli, P. G., Hallbrucker, A., Mayer, E. & Finney, J. L. The preparation and structures of hydrogen ordered phases of ice. Science 311, 1758–1761 (2006).

    ADS  Article  Google Scholar 

  8. 8.

    Pauling, L. The structure and entropy of ice and other crystals with some randomness of atomic arrangement. J. Am. Chem. Soc. 57, 2680–2684 (1935).

    Article  Google Scholar 

  9. 9.

    Tajima, Y., Matsuo, T. & Suga, H. Phase transition in KOH-doped hexagonal ice. Nature 299, 810–812 (1982).

    ADS  Article  Google Scholar 

  10. 10.

    Salzmann, C. G., Radaelli, P. G., Mayer, E. & Finney, J. L. Ice XV: a new thermodynamically stable phase of ice. Phys. Rev. Lett. 103, 105701 (2009).

    ADS  Article  Google Scholar 

  11. 11.

    Lobban, C., Finney, J. L. & Kuhs, W. F. The p–T dependency of the ice II crystal structure and the effect of helium inclusion. J. Chem. Phys. 117, 3928–3834 (2002).

    ADS  Article  Google Scholar 

  12. 12.

    Whalley, E. & Davidson, D. W. Entropy changes at the phase transitions in ice. J. Chem. Phys. 43, 2148–2149 (1965).

    ADS  Article  Google Scholar 

  13. 13.

    Fan, X., Bing, D., Zhang, J., Shen, Z. & Kuo, J.-K. Predicting the hydrogen bond ordered structures of ice Ih, II, III, VI and ice VII: DFT methods with localized based set. Comput. Mater. Sci. 49, S170–S175 (2010).

    Article  Google Scholar 

  14. 14.

    Nakamura, T., Matsumoto, M., Yagasaki, T. & Tanaka, H. Thermodynamic stability of ice II and its hydrogen-disordered counterpart: role of zero-point energy. J. Phys. Chem. B 120, 1843–1848 (2016).

    Article  Google Scholar 

  15. 15.

    Brill, R. & Zaromb, S. Mixed crystals of ice and ammonium fluoride. Nature 173, 316–317 (1954).

    ADS  Article  Google Scholar 

  16. 16.

    Labowitz, L. C. & Westrum, E. F. A thermodynamic study of the system ammonium fluoride-water. II. The solid solution of ammonium fluoride in ice. J. Phys. Chem. 65, 408–414 (1961).

    Article  Google Scholar 

  17. 17.

    Shin, K. et al. Crystal engineering the clathrate hydrate lattice with NH4F. CrystEngComm 16, 7209–7217 (2014).

    Article  Google Scholar 

  18. 18.

    Park, S., Lim, D., Seo, Y. & Lee, H. Incorporation of ammonium fluoride into clathrate hydrate lattices and its significance in inhibiting hydrate formation. Chem. Comm. 51, 8761–8764 (2015).

    Article  Google Scholar 

  19. 19.

    Lyashchenko, A. K. & Malenkov, G. G. X-ray investigation of ammonium fluoride-ice systems. Zh . Strukt. Khimii 10, 724–725 (1969).

    Google Scholar 

  20. 20.

    Wilson, G. J., Chan, R. K., Davidson, D. W. & Whalley, E. Dielectric properties of ices II, III, V, and VI. J. Chem. Phys. 43, 2384–2391 (1965).

    ADS  Article  Google Scholar 

  21. 21.

    Slater, J. C. Theory of the transition in KH2PO4. J. Chem. Phys. 9, 16–33 (1941).

    ADS  Article  Google Scholar 

  22. 22.

    Jaubert, L. D. C., Chalker, J. T., Holdsworth, P. C. W. & Moessner, R. Spin ice under pressure: symmetry enhancement and infinite order multicriticality. Phys. Rev. Lett. 105, 087201 (2010).

    ADS  Article  Google Scholar 

  23. 23.

    Powell, S. Higgs transitions of spin ice. Phys. Rev. B 84, 094437 (2011).

    ADS  Article  Google Scholar 

  24. 24.

    Nagle, J. F. Theory of biomembrane phase transitions. J. Chem. Phys. 58, 252–264 (1973).

    ADS  Article  Google Scholar 

  25. 25.

    Onsager, L. & Dupuis, M. in Termodinamica dei Processi Irreversibili: Rendiconti della Scuola Internazionale di Fisica “Enrico Fermi”, Corso X, Varenna sul Lago di Como, Villa Monasterio, 15-27 Giugno 1959 (ed. de Groot, S. R.) 294–315 (N. Zanichelli, Modena, 1960).

  26. 26.

    Bramwell, S. T. & Harris, M. J. Frustration in Ising-type spin models on the pyrochlore lattice. J. Phys. Condens. Matter 10, L215 (1998).

    ADS  Article  Google Scholar 

  27. 27.

    Ryzhkin, I. A. Magnetic relaxation in rare-earth oxide pyrochlores. J. Exp. Theor. Phys. 101, 481–486 (2005).

    ADS  Article  Google Scholar 

  28. 28.

    Kuhs, W. F., Finney, J. L., Vettier, C. & Bliss, D. V. Structure and hydrogen ordering in ices VI, VII, and VIII by neutron powder diffraction. J. Chem. Phys. 81, 3612–3623 (1984).

    ADS  Article  Google Scholar 

  29. 29.

    Kamb, B., Hamilton, W. C., La Placa, S. J. & Prakash, A. Ordered proton configuration in ice II, from single-crystal neutron diffraction. J. Chem. Phys. 55, 1934–1945 (1971).

    ADS  Article  Google Scholar 

  30. 30.

    Bull, C. L. et al. PEARL: the high pressure neutron powder diffractometer at ISIS. High Pressure Res. 36, 493–511 (2016).

    ADS  Article  Google Scholar 

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We thank the Royal Society (UF150665) and the Leverhulme Trust (RPG-2014-04) for funding, the ISIS facility for granting access to the PEARL instrument, C. Ridley for help with the PEARL pressure equipment, M. Vickers for help with the X-ray measurements, J. K. Cockcroft for access to the Cryojet, and S. L. Price, A. K. Soper and P. A. McClarty for helpful discussions. We also acknowledge the use of the ARCHER UK National Supercomputing Service ( through the Materials Chemistry Consortium via EPSRC grant no. EP/L000202 and the EPSRC-funded Centre for Doctoral Training in Advanced Characterisation of Materials for a studentship (EP/L015277/1).

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C.G.S. designed the project; J.J.S. and P.H. conducted the laboratory-based experiments and performed data analyses; C.G.S., J.J.S, M.H. and C.L.B. carried out the neutron diffraction experiments; C.G.S. analysed the neutron diffraction data; S.T.B. and C.G.S developed the statistical mechanics aspects of this work; DFT calculations were carried out by B.S.; C.G.S, S.T.B., B.S. and J.J.S. wrote the manuscript and prepared the figures; all authors discussed the results and commented on the manuscript.

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Correspondence to Christoph G. Salzmann.

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Shephard, J.J., Slater, B., Harvey, P. et al. Doping-induced disappearance of ice II from water’s phase diagram. Nature Phys 14, 569–572 (2018).

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