Equation of states for dense ice up to 80 GPa at low-temperature conditions

Hiroshi Fukui; Hirokazu Kadobayashi; Hirotaka Abe; Ryunosuke Takahashi; Hiroki Wadati; Naohisa Hirao

doi:10.1063/5.0084278

Equation of states for dense ice up to 80 GPa at low-temperature conditions

J Chem Phys. 2022 Feb 14;156(6):064504. doi: 10.1063/5.0084278.

Authors

Hiroshi Fukui¹, Hirokazu Kadobayashi², Hirotaka Abe¹, Ryunosuke Takahashi¹, Hiroki Wadati¹, Naohisa Hirao³

Affiliations

¹ Graduate School of Science, University of Hyogo, Kouto 3-2-1, Kamigori, Hyogo 678-1297, Japan.
² National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.
³ Japan Synchrotron Radiation Research Institute, Kouto 1-1-1, Sayo, Hyogo 679-5198, Japan.

PMID: 35168349
DOI: 10.1063/5.0084278

Abstract

We have measured the lattice volume of ice VIII in different pressure-temperature pathways and found that the volume depends on the pathway, implying that deviatoric stress makes the volume larger. Dense ice is in the ice VIII phase with the molar volume of 6.56 cm³ and in a high-pressure phase with the molar volume of 6.45 cm³ at 10 K where the pressure can be estimated as 57.0 ± 3.4 and 60.4 ± 3.6 GPa, respectively, based on the third-order Birch-Murnaghan equation with parameters determined in this study (K₀ = 30.8 ± 1.3 GPa and K'₀ = 3.7 ± 0.1 with V₀ fixed to 12.030 cm³).