Superionic-Superionic Phase Transitions in Body-Centered Cubic H2O Ice

Abstract : From first-principles molecular dynamics, we investigate the relation between the superionic proton conduction and the behavior of the O-H ... O bond (ice VII' to ice X transition) in body-centered-cubic (bcc) H2O ice between 1300 and 2000 K and up to 300 GPa. We bring evidence that there are three distinct phases in the superionic bcc stability field. A first superionic phase characterized by extremely fast diffusion of highly delocalized protons (denoted VII\textquotedblright hereinafter) is stable at low pressures. A first-order transition separates this phase from a superionic VII\textquotedblright, characterized by a finite degree of localization of protons along the nonsymmetric O-H ... O bonds. The transition is identified in structural, energetic, and elastic analysis. Upon further compression a second-order phase transition leads to the superionic ice X with symmetric O-H-O bonds.
Document type :
Journal articles
Complete list of metadatas

https://hal-univ-lyon1.archives-ouvertes.fr/hal-02333289
Contributor : Depot 2 Lyon 1 <>
Submitted on : Friday, October 25, 2019 - 11:52:40 AM
Last modification on : Tuesday, February 18, 2020 - 3:54:03 PM

Links full text

Identifiers

Collections

Citation

Jean-Alexis Hernandez, Razvan Caracas. Superionic-Superionic Phase Transitions in Body-Centered Cubic H2O Ice. Physical Review Letters, 2016, 117 (13), ⟨10.1103/PhysRevLett.117.135503⟩. ⟨hal-02333289⟩

Share

Metrics

Record views

27