Strength and Elasticity of Mantle Minerals by Radial X-Ray Diffraction and Brillouin Spectroscopy

在这个项目中，研究人员将在金刚石砧细胞中结合新的径向x射线衍射技术和布里渊光谱技术来研究地幔矿物的流变学和弹性特性。射线x射线衍射是一种新的高压方法，可以约束单晶弹性常数、屈服强度、强度各向异性、应力连续性、织构甚至状态方程的丰富信息。相对于其他测定强度和弹性的技术，径向衍射的优点是可达的压力范围可达下地幔深处，并且不需要高质量的单晶。本研究的一个主要目标是通过选择一组材料来探索径向x射线衍射的能力，研究人员可以同时对这些材料施加60 GPa的径向衍射和20 GPa的单晶布里渊散射。这将提供由新的晶格应变方法和成熟的布里渊技术确定的弹性的直接比较。要检查的具体材料包括钙钛矿、菱镁矿、尖晶石、刚玉、水镁石和氧化钙。这些结果将对高压研究和我们对地球深部地幔的理解具有基础和广泛的应用。

DuffyEAR-0125675In this project, the investigators will study rheological and elastic properties of mantle minerals by combining new radial x-ray diffraction techniques with Brillouin spectroscopy in a diamond anvil cell. Radial x-ray diffraction is a new high-pressure method that can constrain a wealth of information about single-crystal elastic constants, yield strength, strength anisotropy, stress continuity, texturing, and even the equation of state. Advantages of radial diffraction relative to other techniques for strength and elasticity determination are that the accessible pressure range reaches into the deep lower mantle and there is no requirement for high-quality single crystals. A major goal of this study is to explore the capabilities of radial x-ray diffraction by choosing a set of materials for which the investigators can simultaneously apply radial diffraction to 60 GPa and Brillouin scattering on single crystals to 20 GPa. This will provide a direct comparison of elasticity determined by the new lattice strain methods with well-established Brillouin techniques. Specific materials to be examined included perovskites, magnesiowustites, spinel, corundum, brucite, and calcium oxide. These results will have fundamental and wide applications to high-pressure studies and our understanding of the Earth's deep mantle.