Dynamic compression effects of H₂⁡O in a dynamic diamond anvil cell: Origin of metastable ice VII and its crystal growth kinetics

Journal Article · 09 March 2025 · Physical Review. B

DOI: https://doi.org/10.1103/PhysRevB.111.104105 · OSTI ID:2530229

Howard, Alex  ^[1]; Kim, Minseob  ^[1]; Smith, Jesse  ^[2]; Yoo, Choong-Shik  ^[1]

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1. Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics
2. Argonne National Laboratory (ANL), Argonne, IL (United States). High Pressure Collaborative Access Team (HPCAT)

We report on the structural verification of metastable ice VII solidifying in the phase space of ice VI at 1.80 GPa at room temperature. Using time-resolved (TR) x-ray diffraction and TR ruby luminescence paired with high-speed microphotography utilizing a dynamic diamond anvil cell, an initial compression rate range from 0.12 to 95.84 GPa/s was explored. The solidification pressure of metastable ice VII has a potential sigmoidal dependence upon compression rate with a turnover compression rate of ∼80 GPa/s. The preferred crystallization of ice VII in the stability field of ice VI is due to the increased nucleation rate of ice VII over ice VI at 1.77 GPa that is driven by the surface energy difference between the liquid and solid phases along with the change in Gibbs free energy of solidification. The dynamic pressure-volume–compression behaviors of ice phases (VI and VII) show a lattice stiffening in both phases, especially during the compression loading. It is also found that the compression rate greatly affects the solid-solid phase transition between ice VI and VII but does not affect the liquid-solid transition between water and ice VI as much. Lastly, a third phase transition was found to occur after metastable ice VII transforms into high-density amorphous (HDA) ice, which could be a disordered hydrogen-bonded network configuration of ice VII forming out of HDA ice facilitated by the decoupling of the oxygen movement and reorientation of the H_2⁡O molecule. These results demonstrate the complexity of a seemingly simple molecule H_2⁡O, how it can readily change its static properties with the modification of (de)compression rate, and highlight the need to use multiple TR structural and spectroscopic probes at higher time resolutions to realize the most comprehensive understanding.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC02-06CH11357; NA0004091
• OSTI ID: 2530229
• Journal Information: Physical Review. B, Journal Name: Physical Review. B Journal Issue: 10 Vol. 111; ISSN 2469-9969; ISSN 2469-9950
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English