Mineralogical Applications of Transmission Electron Microscopy and Energy-Filtered TEM

透射电子显微镜和能量过滤 TEM 的矿物学应用

• 批准号: 0073955
• 负责人: David Veblen
• 金额: $ 43.8万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073955&HistoricalAwards=false
• 关键词: Mineralogical; Applications; Transmission; Electron; Microscopy

VeblenEAR-0073955This proposal is a renewal of a previous research program that involved applications of transmission electron microscopy (TEM) and ancillary techniques to problems important to the fields of mineralogy, petrology, and geochemistry. In this renewal, several diverse projects are proposed with an underlying thread of trying to understand the crystal chemistry of minerals and their reactions at the sub-nanometer scale. These projects will make use of a new NSF-supported, 300-kV TEM with a field-emission gun, an instrument that has excellent resolution for normal high-resolution TEM experiments and has revolutionized our chemical capabilities. The primary emphasis of the work proposed will be the exploration of how these new analytical capabilities can be applied to mineralogy and geology, as applications of this technique to the earth sciences so far have been largely unexplored. It is proposed to attempt direct chemical analysis of a number of mineral microstructures that are in the size range of less than one to a few unit cells. These include stacking faults, twin planes, and antiphase boundaries in pyroxenes and other minerals; the C domains in calcian dolomite; the fine-scale chemical modulations associated with spinodal decompositions in pyroxenes and feldspars; and Guinier-Preston zones that form during kinetically arrested exsolution in chain silicates. In addition, efforts to achieve quantification using these new analytical methods will be continued. Other projects to be pursued include explorations of structural disorder and chemical variation in newly synthesized, Na- and K-bearing, high-pressure pyriboles that contain alternating single and double silicate chains; of possible relationships between chemical composition and superstructures in the sulfides bornite and digenite; of order-disorder relationships in hibonite and other minerals of the magnetoplumbite group.

Veblenechte-0073955该提案是以前研究计划的更新，该计划涉及透射电子显微镜（TEM）和辅助技术在矿物学、岩石学和地球化学领域重要问题中的应用。 在这次更新中，提出了几个不同的项目，其基本思路是试图了解矿物的晶体化学及其在亚纳米尺度上的反应。 这些项目将使用一种新的NSF支持的300 kV TEM，带有场发射枪，这种仪器对于正常的高分辨率TEM实验具有出色的分辨率，并彻底改变了我们的化学能力。拟议工作的主要重点将是探索如何将这些新的分析能力应用于矿物学和地质学，因为迄今为止这种技术在地球科学中的应用在很大程度上尚未探索。 建议尝试对尺寸范围小于一个到几个晶胞的一些矿物微观结构进行直接化学分析。 这些包括堆垛层错，双晶面，和反相边界的辉石和其他矿物;钙白云石中的C域;细尺度的化学调制与辉石和尖晶石的旋节分解;和吉尼尔普雷斯顿区，形成动力学逮捕出溶在链状硅酸盐。此外，将继续努力利用这些新的分析方法实现量化。 其他拟进行的项目包括探索新合成的、含钠和钾的、含有交替的单硅酸盐链和双硅酸盐链的高压梨石的结构紊乱和化学变化;硫化物硫铁矿和蓝辉铜矿的化学成分和超结构之间的可能关系;黑云母和磁铅石组的其他矿物的有序-无序关系。