Solid State Geochemistry: High-Resolution Transmission Electron Microscopy of Minerals

对于具有地球物理意义的造岩矿物，将以前所未有的细节确定近原子尺度的材料性质和结构扰动。定量测量将包括：低角晶界作为位错密度函数的起伏度；位错和晶界产生的细尺度位移和应变；位错核附近的空间分辨应变能密度-以前无法进入的区域；解离位错的应变场和能量。几何相位分析，结合了高分辨率的透射电子显微镜和密集的图像分析，将被使用。测量结果将与利用弹性理论的计算结果进行比较。在此过程中，将确定距离晶体断裂近一到两个原子间距的区域的弹性常数。研究结果将对材料的变形、再结晶、扩散、电性能和其他地球物理参数产生影响。从应用的角度来看，某些宏观边界几何将给出曲率，可以利用这些曲率来设计所需的特性。具有不同背景和种族的学生和博士后研究人员将提供跨学科的研究环境，并将在纳米尺度上研究材料的先进方法方面进行培训。将发展研究地质材料的新方法；这些程序和数据对从事固态物理、化学和材料科学的科学家也很有用。研究成果将通过在读者广泛的主要期刊上迅速发表来传播。国际部分是通过经常使用我们的设施和技术并将其出口到其本国机构和国家的访客提供的。

Material properties and structural perturbations at the near-atomic scale will be determined with unprecedented detail for rock-forming minerals having geophysical significance. Quantitative measurements will be made of: the waviness of low-angle grain boundaries as a function of dislocation densities; fine-scale displacements and strain produced by dislocations and grain boundaries; the spatially resolved strain-energy density near dislocation cores - regions that were previously inaccessible; and the strain fields and energies of dissociated dislocations. Geometric phase analysis, which combines high-resolution transmission electron microscopy and intensive image analysis, will be used. The measurements will be compared to calculations utilizing elastic theory. In the process, estimates of elastic constants for regions as close as one or two atomic spacings from crystallographic disruptions will be determined. The results will have implications for material properties that include deformation, recrystallization, diffusion, electrical properties and other parameters of geophysical interest. From an applied perspective, certain macroscopic boundary geometries will give curvatures that could be exploited to engineer desired properties. Students and postdoctoral researchers with diverse backgrounds and ethnicities will be provided an interdisciplinary research environment and will be trained in advanced methods of studying materials at the nanoscale. New methodologies for studying geologic materials will be developed; the procedures and data will also be useful for scientists working in solid-state physics, chemistry, and materials science. The products of the research will be disseminated via prompt publication in leading journals with broad readership. An international component is provided through visitors who routinely utilize our facilities and techniques and export them to their home institutions and countries.