Liquid or Solid? Using Pressure-Shear Plate Impact Experiments to Probe the Ice VII Phase of Water

Despite water’s broad ecological presence, its high pressure dynamic properties are not well understood. This work investigates the phase transformation of water to the ice VII phase by studying the material under pressure-shear loading conditions. In the experiments, a thin layer of water is quasi-isentropically compressed to stresses between 0-10 GPa, and a shear wave is imposed on the material. The amplitude and structure of the shear wave is then used to diagnose and assess the phase and kinetics of the transformation. Results suggest the technique is a high-fidelity phase change diagnostic for assessing the dynamic process in water and can assist in probing phase changes when conventional diagnostics are rendered ineffective. Experiments and modelling efforts will be discussed in detail with respect to the material.