title: Ice VII from aqueous salt solutions: From a glass to a crystal with broken H-bonds.
abstract: It has been known for decades that certain aqueous salt solutions of LiCl and LiBr readily form glasses when cooled to below ≈160 K. This fact has recently been exploited to produce a « salty » high-pressure ice form: When the glass is compressed at low temperatures to pressures higher than 4 GPa and subsequently warmed, it crystallizes into ice VII with the ionic species trapped inside the ice lattice. Here we report the extreme limit of salt incorporation into ice VII, using high pressure neutron diffraction and molecular dynamics simulations. We show that high-pressure crystallisation of aqueous solutions of LiCl∙RH2O and LiBr∙RH2O with R = 5.6 leads to solids with strongly expanded volume, a destruction of the hydrogen-bond network with an isotropic distribution of water-dipole moments, as well as a crystal-to-amorphous transition on decompression. This highly unusual behaviour constitutes an interesting pathway from a glass to a crystal where translational periodicity is restored but the rotational degrees of freedom remaining completely random.
authors: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre-et-Marie-Curie, F-75252 Paris, France.
authors: S
authors: S
authors: Klotz
authors: Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors: K
authors: K
authors: Komatsu
authors: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre-et-Marie-Curie, F-75252 Paris, France.
authors: F
authors: F
authors: Pietrucci
authors: Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors: H
authors: H
authors: Kagi
authors: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre-et-Marie-Curie, F-75252 Paris, France.
authors: A-A
authors: AA
authors: Ludl
authors: CROSS-Tokai, Research Centre for Neutron Science and Technology, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan.
authors: S
authors: S
authors: Machida
authors: J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan.
authors: T
authors: T
authors: Hattori
authors: J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan.
authors: A
authors: A
authors: Sano-Furukawa
authors: Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS UMR 7590, Université Pierre-et-Marie-Curie, F-75252 Paris, France.|Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors: L E
authors: LE
authors: Bove