Surface Structure of Oxides

氧化物的表面结构

• 批准号: 1206320
• 负责人: Laurence Marks
• 金额: $ 17.17万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-15 至 2015-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206320&HistoricalAwards=false
• 关键词: Surface; Structure; Oxides

NON-TECHNICAL DESCRIPTION: Oxide surfaces are increasingly important for both scientific and technological areas ranging from more energy-efficient catalysts to new types of electronic devices. Currently not enough is understood about the structure of oxide surfaces to predict what type of materials will be best for future needs. This project is developing tools to understand both the structure of oxide surfaces, as well as how they react with gaseous species. The tools that are developed can then be used by others who are designing interfaces involving these systems, or are exploring their use in new fuel cells, more efficient water-splitting catalysts or substrates upon which to grow new types of oxide-based electronic devices.TECHNICAL DETAILS: The strategy employed combines extended density-functional theory (DFT) methods including exact-exchange hybrids and the bond-valence chemical concepts in a combined experimental-theoretical approach exploiting some unique ultra-high vacuum (UHV) electron microscopy facilities. The main experimental tools are transmission electron microscopy imaging and diffraction to solve the surface structures. In addition to using DFT methods for the surface structures found, the research team is expanding the database of published atomic positions and tests of the bond-valence approach by performing calculations on other oxide surfaces where full details of the atomic positions are not publically available. One additional component is developing algorithms for DFT and related optimization codes, particularly quasi-Newton methods. The software for DFT has already been incorporated into one large package used by more than 1800 groups around the world (www.numis.northwestern.edu). In terms of education, the research helps support both local outreach to high-school students as part of existing programs, as well as more international efforts involving the general public license (GNU) software electron direct methods (edm).

非技术描述：氧化物表面对于从更节能的催化剂到新型电子设备的科学和技术领域越来越重要。目前对氧化物表面结构的了解还不够，无法预测哪种类型的材料最适合未来的需求。该项目正在开发工具，以了解氧化物表面的结构，以及它们如何与气态物质反应。开发的工具可以被其他人使用，这些人正在设计涉及这些系统的接口，或者正在探索它们在新燃料电池、更有效的水分解催化剂或基质中的用途，在这些基质上生长新型氧化物基电子器件。技术支持：所采用的策略结合了扩展的密度泛函理论（DFT）方法，包括精确交换杂化物和键-价化学概念的实验-理论相结合的方法，利用一些独特的超高真空（UHV）电子显微镜设施。主要的实验工具是透射电子显微镜成像和衍射来解决表面结构。除了对发现的表面结构使用DFT方法外，研究团队还通过对原子位置的完整细节尚未公开的其他氧化物表面进行计算来扩展已发布的原子位置数据库和键价方法的测试。另一个组成部分是开发DFT算法和相关的优化代码，特别是准牛顿方法。DFT软件已经被整合到一个大型软件包中，供全球1800多个团体使用（www.numis.northwestern.edu）。在教育方面，这项研究有助于支持当地的高中生外展作为现有计划的一部分，以及涉及通用公共许可证（GNU）软件电子直接方法（edm）的更多国际努力。