MRI: Acquisition of an Aberration Corrected Low Energy Electron Microscope (AC-LEEM) for high resolution spectroscopic imaging of surfaces

该奖项来自重大研究仪器计划，支持哈佛大学购买一种新型显微镜，称为“低能电子显微镜”，为不同环境条件下的材料表面可视化提供了革命性的可能性。 这款新型显微镜将探索表面科学研究的前沿领域，能够在动态模式下可视化反应效果，表面改性，表面重建和在操作条件下研究材料。这种显微镜适用于广泛的研究领域，如催化，能量存储，能量转移，量子材料科学，纳米线，薄膜，光伏和钙钛矿稳定性。这一尖端仪器将为下一代电子产品、储能技术（例如电池）或先进国防应用的基础和应用材料研究开辟新的途径。 这种新的显微镜将安装在纳米系统中心（CNS），该中心是NSF国家纳米技术协调基础设施网络（NNCI）的成员，是一个完全开放的访问环境。该工具将使来自全国多个机构的学生和研究人员能够接受前沿科学技术和方法的教育。 有了这个奖项从主要研究仪器计划哈佛大学将获得一种新型的显微镜，像差校正低能电子显微镜（AC-LEEM）。LEEM是表面分析的关键新前沿技术之一，具有以动态模式可视化反应效果、表面改性、重建和原位研究的能力。 AC-LEEM将安装在纳米系统中心（CNS）的开放访问环境中，该中心是NSF国家纳米技术协调基础设施网络（NNCI）的成员。该仪器支持来自广泛国家基础的研究人员，适用于广泛的材料研究领域，如催化，能量存储，能量转移，量子材料科学，纳米线，薄膜，光伏和钙钛矿稳定性。这一尖端仪器将为基础和应用研究开辟新的途径。 LEEM使研究人员能够通过成像（LEEM），衍射（LEED）和光谱学（光学和电子）来探索表面状态和表面界面，同时动态加热/冷却样品并允许添加气体（反应性或其他）以提供动态表面修改和重建的可视化。该系统允许样品被加热到1500度。C. 该系统允许控制气体注入，以微调表面重建和修改的速度。该系统采用紫外光源进行角度分辨光电子能谱（ARPES）。还可以进行高分辨率电子能谱（ES）和绘图。 在国家用户设施中的放置允许学生和研究人员使用这种先进的表面分析仪器。 该仪器将通过研究生、本科生和成人教育层面的“纳米级成像和分析”创新教育计划，融入材料科学、物理学、化学和催化学的教学。它将加强本科教育研究（REU），教师研究经验（RET）和退伍军人研究经验（REV）计划，并将使学生和教师接触尖端技术，以及CNS教育推广模式，如研讨会，短期课程和“开放日”，以向更广泛的受众传播新信息。 该显微镜将使美国在材料科学研究和教育方面具有竞争优势。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award from the Major Research Instrumentation program supports Harvard University with the acquisition of a new type of microscope called a "Low Energy Electron Microscope" which provides revolutionary possibilities for visualization of material surfaces in different environmental conditions. This new microscope will explore the frontiers for surface science research with the ability of visualizing reaction effects in a dynamic mode, surface modifications, surface reconstruction and studies of materials in operating conditions. This microscope is applicable to a wide range of research areas, such as catalysis, energy storage, energy transfer, quantum materials science, nanowires, thin films, photovoltaic and perovskite stability. This cutting-edge instrument will open new avenues for fundamental and applied materials research for next generation of electronics, for energy storage technologies (batteries for example) or for advanced defense applications. This new microscope will be installed at the Center for Nanoscale Systems (CNS), which is a member of the NSF's National Nanotechnology Coordinated Infrastructure Network (NNCI) and a fully open access environment. This instrument will enable the education of students and researchers from multiple institutions across the county in leading-edge science techniques and methodology. With this award from the Major Research Instrumentation program Harvard University will acquire a new type of microscope, an Aberration Corrected Low Energy Electron Microscope (AC-LEEM). LEEM is one of the critical new frontiers techniques for surface analysis with the ability of visualizing reaction effects in a dynamic mode, surface modifications, reconstructions and in-situ research. The AC-LEEM will be installed in an open access environment at the Center for Nanoscale Systems (CNS), which is a member of the NSF's National Nanotechnology Coordinated Infrastructure Network (NNCI). This instrument supports researchers from a broad national base and is applicable to a wide range of materials research areas, such as catalysis, energy storage, energy transfer, quantum materials science, nanowires, thin films, photovoltaic and perovskite stability. This cutting-edge instrument will open new avenues for fundamental and applied research. LEEM enables researchers to explore surface states and surface interfaces, by imaging (LEEM), diffraction (LEED) and spectroscopies, both optical and electron, in extreme detail while dynamically heating/cooling the sample and allowing the addition of a gas (reactive or otherwise) to provide visualization of dynamic surface modifications and reconstructions. This system allows the sample to be heated up to 1500 deg. C. The system allows control of the gas injection for fine-tuning the speed of surface reconstructions and modification. The system incorporates an Ultraviolet light source for Angle-Resolved Photoemission Spectroscopy (ARPES). High resolution Electron Energy Spectroscopy (ES) and mapping can also be performed. The placement in a national user facility allows students and researchers access to this advanced surface analytical instrumentation. This instrument will be integrated into the teaching of materials science, physics, chemistry and catalysis through innovative new educational programs on "nanoscale imaging and analysis" at the graduate, undergraduate and adult education levels. It will enhance Research in Undergraduate Education (REU), Research Experiences for Teachers (RET) and Research Experiences for Veterans (REV) programs and will allow students and teachers to be exposed to cutting edge technology, and the CNS educational outreach models such as workshops, short courses and "open houses" to disseminate new information to a broader audience. This microscope will give the Unites States a competitive edge in materials science research and education.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.