Rheological properties of planetary ices at high pressure

行星冰的流变特性是理解冰卫星和行星内部对流的关键问题之一。利用气体介质多砧高压变形装置和金刚石对顶砧装置，结合同步辐射和显微拉曼光谱技术，对不同行星冰进行了高压相变、塑性变形、晶粒生长和原子扩散实验。这些技术使我们能够在比以前进行的高得多的压力下研究冰的流变学。我们新观察到的蠕变强度的冰VII，削弱H2O冰由于少量的CO2冰，应变能的影响，在冰VI-VII转变的生长动力学，和晶界扩散多晶冰。

Rheological properties of planetary ices are one of key issues to understand the convecting interiors of icymoons and planets. We conducted high-pressure transformation, plastic deformation, grain growth, andatomic diffusion experiments for various planetary ices by using gas-medium and multi-anvil high-pressuredeformation apparatus and diamond anvil cell combined with synchrotron radiation and micro-Ramanspectroscopy. These techniques enable us to examine the ice rheology at much higher pressures thanpreviously conducted. We newly observed creep strength of ice VII, weakening of H2O ice due to smallamounts of CO2 ices, effects of strain energy on the growth kinetics in the ice VI-VII transformation, andgrain-boundary diffusion in polycrystalline ice.