Collaborative Research: CDS&E: Experimentally verified nano-oxidation simulations of Cu surfaces

合作研究：CDS

• 批准号: 1410055
• 负责人: Judith Yang
• 金额: $ 43.5万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410055&HistoricalAwards=false
• 关键词: Collaborative; Research; CDS&E; Experimentally; verified

NON-TECHNICAL SUMMARYThere is a great deal of knowledge about the oxidation of metal surfaces on macroscopic scales, but very little is known about how the process starts at the smallest molecular scales. Understanding the oxidation phenomena that occur at such nanometer (one billionth the size of a meter) length scales is of both scientific and technological importance, since more and more materials are being engineered at nanometer scales for practical applications. The stability of such nanoscale materials cannot necessarily be inferred directly from the knowledge about their bulk counterparts, and new theories are needed to predict material properties at such small scales. This collaborative project brings together a theoretical chemist who will model the individual reaction mechanisms of the oxidation of a copper surface, a theoretical physicist who will combine these mechanisms in a statistical model of the oxide growth kinetics, and finally an experimental microscopist who can watch the growth of nanometer scale oxide islands with an electron microscope. This research team will work together to understand the initial oxidation of copper surface, from the atomic scale on and up. New simulation methodologies will be developed as part of this effort. The software that will be developed and used to model the oxidation will be released freely to other researchers and to the public. The techniques will also be incorporated into graduate-level courses and as part of high-school outreach programs both in Austin, TX and Pittsburgh, PA. TECHNICAL SUMMARY This award supports a collaborative research and education effort between the University of Pittsburgh and the University of Texas at Austin for developing materials computational tools that can be used to model nano-oxidation, and to correlate computational predictions with experimental observations. The PIs will integrate versatile codes for modeling dynamics at surfaces and address three key challenges in the proposed research, which are (i) to use accelerated dynamics methods and off-lattice adaptive kinetic Monte Carlo (KMC) with empirical potentials and density functional theory to extract the reaction mechanisms of surface oxidation, (ii) to continue the development of the Thin Film Oxidation KMC approach, particularly taking it from 2 to 3 dimensions, and (iii) to develop a method for coarse graining the representations of reaction mechanisms found with adaptive KMC to provide the event tables for the three-dimensional Thin Film Oxidation code. These studies will provide realistic input parameters for the Thin Film Oxidation simulations, allow for critical insights to be made into the nucleation behavior, morphological evolution of oxide islands during nano-oxidation and coalescence, and provide the surface and interface energies required to understand island stability. This collaboration builds on existing infrastructure, including the experimental electron microscopy effort in Pittsburgh and the theoretical and software efforts in Austin and Pittsburgh. This research team will work together to understand the initial oxidation of a copper surface, from the atomic scale on and up. The software that will be used to model the oxidation will be released freely to other researchers and to the public. The techniques will also be incorporated into graduate-level courses and as part of high-school outreach programs both in Austin and Pittsburgh.

非技术摘要关于宏观尺度上金属表面的氧化有大量知识，但对于该过程如何在最小分子尺度上开始却知之甚少。 了解在这种纳米（十亿分之一米大小）长度尺度上发生的氧化现象具有科学和技术上的重要性，因为越来越多的材料正在纳米尺度上进行设计以用于实际应用。 这种纳米级材料的稳定性不一定可以直接从其块体对应物的知识中推断出来，并且需要新的理论来预测如此小尺度的材料特性。 该合作项目汇集了一位理论化学家，他将模拟铜表面氧化的各个反应机制；一位理论物理学家，将这些机制结合到氧化物生长动力学的统计模型中；最后，还有一位实验显微镜师，他可以用电子显微镜观察纳米级氧化物岛的生长。 该研究小组将共同努力从原子尺度及以上了解铜表面的初始氧化。 作为这项工作的一部分，将开发新的模拟方法。将开发并用于模拟氧化的软件将免费发布给其他研究人员和公众。 这些技术还将被纳入德克萨斯州奥斯汀和宾夕法尼亚州匹兹堡的研究生课程和高中推广计划的一部分。 技术摘要 该奖项支持匹兹堡大学和德克萨斯大学奥斯汀分校之间的合作研究和教育工作，以开发可用于模拟纳米氧化并将计算预测与实验观察相关联的材料计算工具。 PI 将集成用于表面动力学建模的通用代码，并解决拟议研究中的三个关键挑战，即（i）使用加速动力学方法和离格自适应动力学蒙特卡罗（KMC）以及经验势和密度泛函理论来提取表面氧化的反应机制，（ii）继续开发薄膜氧化 KMC 方法，特别是将其从 2 提高到 3 (iii) 开发一种粗粒度化自适应 KMC 发现的反应机制表示的方法，为三维薄膜氧化代码提供事件表。这些研究将为薄膜氧化模拟提供真实的输入参数，允许对纳米氧化和聚结过程中氧化物岛的成核行为、形态演化进行关键洞察，并提供了解岛稳定性所需的表面和界面能量。这项合作建立在现有基础设施的基础上，包括匹兹堡的实验电子显微镜工作以及奥斯汀和匹兹堡的理论和软件工作。 该研究团队将共同努力，从原子尺度及以上了解铜表面的初始氧化。 用于模拟氧化的软件将免费发布给其他研究人员和公众。 这些技术还将被纳入研究生课程，并作为奥斯汀和匹兹堡高中推广计划的一部分。