1. Melting Curve and Isostructural Solid Transition in Superionic Ice
- Author
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Mohamed Mezouar, J.-A. Hernandez, S. Ninet, Gaston Garbarino, Stefan Klotz, Jean-Antoine Queyroux, Frédéric Datchi, Nicolas Guignot, Gunnar Weck, Thomas Plisson, Jean-Paul Itié, Michael Hanfland, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Center for Earth Evolution and Dynamics, University of Oslo, University of Oslo (UiO), European Synchrotron Radiation Facility (ESRF), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), ANR-13-BS04-0015,MOFLEX,Structure et dynamique des fluides moléculaires simples sous conditions extrêmes de pression et température(2013), and ANR-15-CE30-0008,SUPER-ICES,Phases superioniques, ioniques et symétriques dans les mélanges de glace (H2O, NH3, CH4) sous conditions extrêmes(2015) more...
- Subjects
Diffraction ,Materials science ,Triple point ,General Physics and Astronomy ,Thermodynamics ,01 natural sciences ,Synchrotron ,Diamond anvil cell ,Melting curve analysis ,Ice VII ,Physics::Geophysics ,law.invention ,Condensed Matter::Materials Science ,law ,0103 physical sciences ,Isostructural ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,Phase diagram - Abstract
The phase diagram and melting curve of water ice is investigated up to 45 GPa and 1600 K by synchrotron x-ray diffraction in the resistively and laser heated diamond anvil cell. Our melting data evidence a triple point at 14.6 GPa, 850 K. The latter is shown to be related to a first-order solid transition from the dynamically disordered form of ice VII, denoted ice ${\mathrm{VII}}^{\ensuremath{'}}$, toward a high-temperature phase with the same bcc oxygen lattice but larger volume and higher entropy. Our experiments are compared to ab initio molecular dynamics simulations, enabling us to identify the high-temperature bcc phase with the predicted superionic ice ${\mathrm{VII}}^{\ensuremath{'}\ensuremath{'}}$ phase [J.-A. Hernandez and R. Caracas, Phys. Rev. Lett. 117, 135503 (2016).]. more...
- Published
- 2020
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