Pressure-induced structural modifications in silicate melts play a crucial role in controlling dynamic processes in the deep interiors of the Earth and other planets. The correlation between structural and macroscopic properties of silicate liquids (densification, viscosity, chemical differentiation, etc.), however, remains poorly understood. Here we report the evolution of structural modifications and elastic properties of MgSiO3 glass to pressures up to ~70 GPa using a combination of experimental techniques, including micro-confocal Raman spectroscopy, angle-dispersive X-ray scattering, and Brillouin spectroscopy in the diamond-anvil cell. Our combined data set provides consistent and complementary evidence of a series of pressure-induced structural modifications in MgSiO3 glass at ~2, ~8, ~20, and ~40 GPa. Based on these results, a structural evolution model for MgSiO3 glass is proposed. We also discuss the role of Mg-O component in MgSiO3 and Mg2SiO4 glasses in controlling pressure-induced structural modifications and mechanical responses in these supercooled liquids.

中文翻译：

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MgSiO3玻璃在地球深部内部动力学行为的多方面实验研究

硅酸盐熔体中压力引起的结构改变在控制地球和其他行星内部深处的动态过程中起着至关重要的作用。然而，硅酸盐液体的结构和宏观性质（致密化、粘度、化学分化等）之间的相关性仍然知之甚少。在这里，我们使用包括微共焦拉曼光谱、角色散 X 射线散射和布里渊光谱在内的实验技术，报告了 MgSiO3 玻璃的结构改性和弹性特性在高达 ~70 GPa 的压力下的演变。砧细胞。我们的组合数据集提供了一致且互补的证据，证明 MgSiO3 玻璃在 ~2、~8、~20 和 ~40 GPa 时发生了一系列压力诱导的结构改性。基于这些结果，提出了MgSiO3玻璃的结构演化模型。我们还讨论了 Mg-O 组分在 MgSiO3 和 Mg2SiO4 玻璃中在控制这些过冷液体中压力引起的结构改变和机械响应中的作用。