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

固态地球化学：矿物的高分辨率透射电子显微镜

• 批准号: 0440388
• 负责人: Peter Buseck
• 金额: --
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-15 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0440388&HistoricalAwards=false
• 关键词: Solid; State; Geochemistry; Resolution; Transmission

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.

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特性和结构扰动。定量测量将包括： 作为位错密度函数的小角度晶界的波纹度；位错和晶界产生的精细位移和应变；位错核心附近的空间分辨应变能密度 - 以前无法到达的区域；以及解离位错的应变场和能量。将使用结合了高分辨率透射电子显微镜和强化图像分析的几何相位分析。测量结果将与利用弹性理论的计算进行比较。在此过程中，将确定晶体破坏中近至一或两个原子间距的区域的弹性常数估计值。研究结果将对材料特性产生影响，包括变形、再结晶、扩散、电特性和其他地球物理参数。从应用的角度来看，某些宏观边界几何形状将给出可用于设计所需特性的曲率。具有不同背景和种族的学生和博士后研究人员将获得跨学科的研究环境，并将接受纳米尺度材料研究先进方法的培训。将开发研究地质材料的新方法；这些程序和数据对于从事固态物理、化学和材料科学工作的科学家也很有用。研究成果将通过在拥有广泛读者群的领先期刊上及时发表来传播。国际成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。