title: Equations of state of ice VI and ice VII at high pressure and high temperature.
abstract: High-pressure H2O polymorphs among which ice VI and ice VII are abundant in the interiors of large icy satellites and exo-planets. Knowledge of the elastic properties of these pure H2O ices at high-temperature and high-pressure is thus crucial to decipher the internal structure of icy bodies. In this study we assess for the first time the pressure-volume-temperature (PVT) relations of both polycrystalline pure ice VI and ice VII at high pressures and temperatures from 1 to 9 GPa and 300 to 450 K, respectively, by using in situ synchrotron X-ray diffraction. The PVT data are adjusted to a second-order Birch-Murnaghan equation of state and give V0 = 14.17(2) cm(3) mol(-1), K0 = 14.05(23) GPa, and α0 = 14.6(14) × 10(-5) K(-1) for ice VI and V0 = 12.49(1) cm(3) mol(-1), K0 = 20.15(16) GPa, and α0 = 11.6(5) × 10(-5) K(-1) for ice VII.
authors.affiliation: European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38000 Grenoble, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Bezacier
authors.affiliation: Laboratoire de Géologie de Lyon, UMR 5276 CNRS, Ecole Normale Supérieure de Lyon - Université Claude Bernard Lyon 1, 2 rue Raphael Dubois, 69622 Villeurbanne Cedex, France.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Journaux
authors.affiliation: Laboratoire de Géologie de Lyon, UMR 5276 CNRS, Ecole Normale Supérieure de Lyon - Université Claude Bernard Lyon 1, 2 rue Raphael Dubois, 69622 Villeurbanne Cedex, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Perrillat
authors.affiliation: Laboratoire de Géologie de Lyon, UMR 5276 CNRS, Ecole Normale Supérieure de Lyon - Université Claude Bernard Lyon 1, 2 rue Raphael Dubois, 69622 Villeurbanne Cedex, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Cardon
authors.affiliation: European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38000 Grenoble, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Hanfland
authors.affiliation: Laboratoire de Géologie de Lyon, UMR 5276 CNRS, Ecole Normale Supérieure de Lyon - Université Claude Bernard Lyon 1, 2 rue Raphael Dubois, 69622 Villeurbanne Cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Daniel