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

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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.