Atomic distribution and local structure in ice VII from in situ neutron diffraction - Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie Accéder directement au contenu
Article Dans Une Revue Proceedings of the National Academy of Sciences of the United States of America Année : 2022

Atomic distribution and local structure in ice VII from in situ neutron diffraction

Résumé

Ice polymorphs show extraordinary structural diversity depending on pressure and temperature. The behavior of hydrogen-bond disorder not only is a key ingredient for their structural diversity but also controls their physical properties. However, it has been a challenge to determine the details of the disordered structure in ice polymorphs under pressure, because of the limited observable reciprocal space and inaccuracies related to high-pressure techniques. Here, we present an elucidation of the disordered structure of ice VII, the dominant high-pressure form of water, at 2.2 GPa and 298 K, from both single-crystal and powder neutron-diffraction techniques. We reveal the three-dimensional atomic distributions from the maximum entropy method and unexpectedly find a ring-like distribution of hydrogen in contrast to the commonly accepted discrete sites. In addition, total scattering analysis at 274 K clarified the difference in the intermolecular structure from ice VIII, the ordered counterpart of ice VII, despite an identical molecular geometry. Our complementary structure analyses robustly demonstrate the unique disordered structure of ice VII. Furthermore, these findings are related to proton dynamics, which drastically vary with pressure, and will contribute to an understanding of the structural origin of anomalous physical properties of ice VII under pressures.
Fichier principal
Vignette du fichier
PureVII_PNAS_accepted_with_proof_corrections.pdf (696.81 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03879209 , version 1 (30-11-2022)

Identifiants

Citer

Keishiro Yamashita, Kazuki Komatsu, Stefan Klotz, Oscar Fabelo, Maria T Fernández-Díaz, et al.. Atomic distribution and local structure in ice VII from in situ neutron diffraction. Proceedings of the National Academy of Sciences of the United States of America, 2022, 119 (40), pp.e2208717119. ⟨10.1073/pnas.2208717119⟩. ⟨hal-03879209⟩
16 Consultations
19 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More