Materials World Network: Mapping Oxide Surface Reactivity Through Spacially-Resolved Atomic Interaction Forces

材料世界网络：通过空间分辨原子相互作用力绘制氧化物表面反应性

• 批准号: 0806893
• 负责人: Udo Schwarz
• 金额: $ 42万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0806893&HistoricalAwards=false
• 关键词: Materials; World; Network; Mapping; Oxide

This is a collaborative research project between Yale University and the Universidad Autonoma de Madrid in Spain. The goal of the project is to characterize the chemical reactivity of individual surface atoms on transition metal oxide surfaces using non-contact atomic force microscopy with functionalized tips. For this purpose, a new technique capable of mapping the strengths of chemical interactions on the atomic scale will be developed through experimentation (carried out in Udo Schwarz' and Eric Altman's groups at Yale University) guided by theory (performed by Ruben Perez' group at the Universidad Autonoma de Madrid). The work builds upon recent demonstration of the ability to experimentally obtain the entire three-dimensional force field acting between a probe tip and surface in the short-range chemical forces regime with atomic resolution. Using this method with tips functionalized to expose electrophilic and nucleophilic head groups allows for the characterization and quantification of the key properties that govern oxide catalysis for individual cations and anions on the surface, in specific site geometries. The new method is initially applied to a comparison of the local chemical properties of Ti cations and O anions on the rutile (110) and anatase (001) surfaces, which, despite chemical and structural similarities, behave markedly differently chemically. For a fundamental understanding of the measured tip-sample interaction, the experimental program couples with a synergistic multi-scale theoretical effort that includes a quantum mechanical description of the short-range chemical forces, a classical description of the longer range dispersion forces, and molecular dynamics simulations of the influence of the forces on the probing geometry.The international collaboration of Yale University and the Universidad Autonoma de Madrid that is at the heart of this project provides a unique educational experience for the graduate and undergraduate students involved in the project. Through extended student exchanges during each year of the project, students are immersed in state-of-the-art experimental and theoretical efforts while being exposed to a truly international research environment. Also, further development of the method as a robust technique promises to impact other fields that are governed by local surface interactions including tribology, thin film growth, electronic device design, and the specific chemical interactions at the center of much of biology.

这是耶鲁大学和西班牙马德里大学的合作研究项目。该项目的目的是使用具有功能化尖端的非接触原子力显微镜来表征单个表面原子在过渡金属氧化物表面上的化学反应性。为此，将通过理论指导（由Ruben Perez'Madrid大学的Ruben Perez'组在Yale University的Udo Schwarz'和耶鲁大学的Eric Altman群体中开发一种能够映射原子量表上化学相互作用强度的新技术（在Udo Schwarz'和耶鲁大学的Eric Altman群体中进行）。这项工作是基于最近证明具有实验性在用原子分辨率的短距离化学力状态下探针尖端和表面之间作用的整个三维力场的能力的基础。使用此方法与尖端进行功能化以暴露亲电和亲核的头部组，可以在特定位点的几何形状中表征和定量，这些关键特性负责控制氧化物催化的单个阳离子和表面上的阴离子。最初，新方法用于比较金红石（110）和解剖酶（001）表面上的局部化学特性，尽管化学和结构相似性，但在化学上的表现明显不同。为了对测得的尖端样本相互作用有基本的了解，实验程序与协同的多尺度理论努力融合，包括对短距离化学力的量子机械描述，对长距离分散力的经典描述，以及分子动力学的经典描述，以及对探针的影响的分子动力学。参与该项目的研究生和本科生的独特教育经验。通过在项目的每一年中扩展的学生交流，学生将沉浸在最新的实验和理论工作中，同时接触到真正的国际研究环境。同样，该方法作为一种强大的技术进一步开发有望影响其他局部表面相互作用，包括摩擦学，薄膜生长，电子设备设计以及许多生物学中心的特定化学相互作用。