Rheological properties of planetary ices at high pressure

行星冰的流变特性是了解冰月和行星对流内部的关键问题之一。利用同步辐射和微拉曼光谱相结合的气体介质多砧高压变形仪和金刚石砧细胞，对各种行星冰进行了高压转变、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高得多的压力下研究冰的流变学。我们新观察到冰VII的蠕变强度、少量CO2冰对H2O冰的削弱、应变能对冰VI-VII相变生长动力学的影响以及多晶冰的晶界扩散。

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.