MRI: Acquisition of a Direct Detection Electron Energy Loss Spectrometer for Fast, Low-Dose, and High Resolution Spectroscopic Imaging of Hard and Soft Materials

这项重大研究仪器(MRI)奖支持购买配备直接电子探测(DED)相机的高速电子能量损失光谱仪(EELS)。该仪器与科罗拉多博尔德大学材料电子显微镜设施的像差校正透射式电子显微镜集成在一起，极大地扩大了这一已经强大的显微镜的用途和地区影响。这种先进的电子能谱仪系统使科学跨越许多领域，包括跨不同部门、研究所、大学、国家实验室和行业的合作。该仪器便于来自更广泛地区的研究生、博士后和研究人员(包括学术界、工业界和国家实验室人员)使用，而且由于其独特的功能，全国各地的科学家都感兴趣。向所有内部和外部用户提供必要的培训和支持。通过与各种校园项目的联系，使用新系统的教师通过分享他们的尖端研究来丰富数百名学生的教育经验。该仪器被整合到研究生和本科课程、针对代表性不足群体的学生、K-12学生和教师的倡议和推广计划中，以培养他们对科学和工程的兴趣。新的EELS系统以高空间分辨率探测材料在紫外区、可见光和红外区的光学和电学性质，能量低至80 MeV。研究人员用原子分辨率测量了边缘结构附近的电子能量损失中包含的元素组成、化学键和氧化状态信息，为材料结构和化学之间的关系提供了新的见解。该仪器还设计为能够在束敏感和低对比度材料(如聚合物和有机薄膜)上进行高分辨率电子成像和光谱分析，同时将电子剂量降至最低。高速DED相机使科学家能够进一步开发电子印刷术技术。DED相机和电子双棱镜的结合使光束敏感材料的相位和光谱成像成为可能。分析了为可再生和可持续能源应用而设计的纳米材料，以便于从原子级电子结构的角度分析热、光和电催化反应的性能。新系统还被用于生物矿物和天然材料的几个应用，例如绘制生物有机体产生的束敏感纳米材料的化学成分图。除了这些具体的例子，来自不同学科的用户还可以询问不同类型材料的原子和电子结构。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Major Research Instrumentation (MRI) award supports the acquisition of a high-speed electron energy loss spectrometer (EELS) equipped with a direct electron detection (DED) camera. This instrument is integrated with an aberration-corrected transmission electron microscope at the Facility for Electron Microscopy of Materials at the University of Colorado Boulder, vastly expanding the utility and regional impact of this already powerful microscope. The science enabled by this advanced electron spectrometer system spans many fields and includes collaborations across diverse departments, institutes, universities, national labs, and industry. The instrument is readily accessible to graduate students, postdocs, and researchers from the broader region (including academic, industry, and national laboratory personnel), and because of unique capabilities, is of interest to scientists around the country. Required training and support are provided to all internal and external users. Through connections with various campus programs, faculty using the new system enrich educational experiences of hundreds of students by sharing their cutting-edge research. The instrument is integrated into graduate and undergraduate courses, initiatives and outreach programs for students from underrepresented groups, K-12 students, and teachers to cultivate their interest in science and engineering.The new EELS system probes optical and electronic properties of materials in ultraviolet, visible, and infrared regions down to energies of 80 meV with high spatial resolution. Researchers measure elemental composition, chemical bonding, and oxidation state information contained in the electron energy loss near edge structures with atomic resolution, providing new insights into the relationship between materials structure and chemistry. The instrumentation is also designed to enable high resolution electron imaging and spectroscopy on beam-sensitive and low-contrast materials, such as polymers and organic thin films, while minimizing electron dose. The high-speed DED camera allows scientists to further develop the technique of electron ptychography. The combination of DED camera and electron biprism enables phase and spectroscopic imaging of beam-sensitive materials. Nanomaterials designed for renewable and sustainable energy applications are analyzed to facilitate the analysis of performance for thermo-, photo-, and electro-catalytic reactions in terms of atomistic-level electronic structure. The new system is also employed for several applications in biominerals and natural materials, such as for mapping the chemical composition of beam-sensitive nanomaterials generated by biological organisms. Beyond these specific examples, users from a wide variety of disciplines interrogate atomic and electronic structures of diverse types of materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.