CAREER: Atomic Structure and Growth of Nano-Particles

职业：原子结构和纳米粒子的生长

• 批准号: 0449790
• 负责人: Jian-Min Zuo
• 金额: $ 61万
• 依托单位: University of Illinois at Urbana-Champaign
• 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: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0449790&HistoricalAwards=false
• 关键词: CAREER; Atomic; Structure; Growth; Nano

This career proposal focuses on the structure of nano-scale atomic aggregates. The problem is important because embryonic clusters or particles form at the early stage of phase transformations and the cluster structure affects the phase transformation and microstructure evolution. Furthermore, metal particles are important industrial catalyst and nanoparticles are the building blocks for nanotechnology. This proposal will develop new approaches to structure characterization and atomic resolution imaging based on the new nano-area electron diffraction (NED) technique involving a nanometer-sized coherent beam of parallel electrons. NED allows diffraction patterns to be recorded from individual particles for 3-D structure determination. The results will contribute to the understanding of atomic structure in nanoparticles. In-situ capabilities will be developed using a modified analytical UHV scanning transmission electron microscope. The analytical capability will be very useful for studying alloying and phase separation in bimetallic nanoparticles. Insight about particle structure will be obtained by comparing experiment with molecular dynamics simulations. A goal of the project is to use the structural knowledge as a feedback to growth to improve the properties of the nano-particles. Materials to be studied include the model system of Ag nanoparticles and the eutectic Ag/Cu system. Later study will focus on magnetic alloys of Ag/Fe and Fe/Pt, and catalytic Pt/Ru to correlate structure with properties.The research will be integrated with education at several levels. This project will develop novel methods that make use of a nanometer-sized coherent beam of parallel electrons to determine atomic arrangements. The technique is general, and in principle, applicable to individual macromolecules. The in-situ capabilities to be developed will be available through the Center for Microanalysis of Materials (CMM) to the broader community. Knowledge gained will be incorporated for teaching nanostructure characterization and used for outreach activities through workshops and schools. An important aspect of the project is the creation of research and education tools in the form of web-based research software and tutorials for educators who seek to incorporate nanoscience in their own curricula. The teaching materials to be developed here will also fill a gap in current materials science education by introducing students to the concept of molecular diffraction. Graduate and undergraduate researchers will be trained through hands-on workshops, conferences and collaboration on nanoscience specific projects.

这项职业建议着重于纳米级原子骨料的结构。问题很重要，因为在相变的早期阶段形成胚胎簇或颗粒，簇结构会影响相变和微观结构的演变。此外，金属颗粒是重要的工业催化剂，纳米颗粒是纳米技术的基础。该建议将根据新的纳米面积电子衍射（NED）技术开发新的结构表征和原子分辨率成像，该技术涉及纳米尺寸的平行电子相干光束。 NED允许从单个颗粒记录衍射图，以确定3-D结构。结果将有助于理解纳米颗粒中的原子结构。原位功能将使用改进的分析UHV扫描透射电子显微镜开发。分析能力对于研究双金属纳米颗粒中的合金和相位分离非常有用。通过将实验与分子动力学模拟进行比较，将获得有关粒子结构的见解。该项目的目标是将结构知识作为增长的反馈，以改善纳米颗粒的特性。要研究的材料包括AG纳米颗粒的模型系统和Eutectic AG/CU系统。后来的研究将重点放在Ag/Fe和Fe/Pt的磁合金上，以及催化PT/RU将结构与特性相关联。该研究将与多个级别的教育集成。该项目将开发新的方法，该方法利用纳米尺寸的平行电子相干光束来确定原子布置。该技术是一般的，原则上适用于单个大分子。将要开发的原位功能将通过材料的微分析中心（CMM）提供给更广泛的社区。获得的知识将被纳入纳米结构表征，并通过研讨会和学校用于外展活动。该项目的一个重要方面是，以基于Web的研究软件的形式创建研究和教育工具，并为寻求在自己的课程中纳入纳米科学的教育工作者的教程。这里要开发的教材还将通过向学生介绍分子衍射的概念来填补当前材料科学教育的空白。 研究生和本科研究人员将通过动手研讨会，会议和特定于纳米科学项目的合作进行培训。