corner
corner

Phys. Rev. B 77, 214103 (2008) [6 pages]

Compression of H2O ice to 126 GPa and implications for hydrogen-bond symmetrization: Synchrotron x-ray diffraction measurements and density-functional calculations

Download: PDF (144 kB) Buy this article Export: BibTeX or EndNote (RIS)

Emiko Sugimura1,*, Toshiaki Iitaka2,†, Kei Hirose1,3, Katsuyuki Kawamura1, Nagayoshi Sata3, and Yasuo Ohishi4
1Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551, Japan
2Computational Astrophysics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
3Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan
4Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan

Received 19 November 2007; revised 8 May 2008; published 11 June 2008

We examined the volume compression and phase transformations of H2O ice by a combination of synchrotron x-ray diffraction measurements and density-functional calculations up to 126 GPa. The experimental data demonstrate that ice changes its compressibility at 40 and 60 GPa at room temperature, corresponding to the phase transitions from ice VII to dynamically disordered ice VII and subsequently to dynamically disordered ice X. The intermediate phase, dynamically disordered ice VII, is highly compressible, possibly due to quantum effects of protons. In contrast, dynamically disordered ice X and ice X show much smaller compressibility.

© 2008 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.77.214103
DOI:
10.1103/PhysRevB.77.214103
PACS:
61.50.Ks, 62.50.−p, 61.05.cp, 31.15.E−

*Corresponding author. sugimura@geo.titech.ac.jp

Corresponding author. tiitaka@riken.jp