Characterization of the thermodynamic stability and mechanical properties of Plastic Ice VII

Molecular Dynamics (MD) simulations predicted the existence of a plastic phase of Ice VII more than a decade ago, however its experimental observation has remained elusive. Recently we obtained the first experimental identification of such phase by high pressure and high temperature quasi-elastic neutron scattering experiments performed at ILL. We here propose to perform an X-Ray Diffraction experiment on ID15B in order to assess some of the open questions regarding this new phase of Ice. We aim at understanding the order of the phase transition, determining the pressure-temperature stability range, and characterizing the mechanical properties of such phase.

分子动力学（Molecular Dynamics, MD）模拟于十余年前便预言了冰VII（Ice VII）存在塑性相，但该物相的实验观测始终未能实现。近期，我们借助在国际劳厄-朗之万研究所（Institut Laue-Langevin, ILL）开展的高温高压准弹性中子散射实验，首次完成了该物相的实验鉴定。我们提议在ID15B光束线开展X射线衍射（X-Ray Diffraction, XRD）实验，以解答该新型冰相相关的若干悬而未决的问题。本研究旨在明确该相变的级数、确定其温压稳定区间，并表征该物相的力学特性。