MRI: Acquisition of a Dual-EELS Gatan Quantum Imaging Spectrometer to Upgrade the JEOL ARM200CF at UIC.

低维材料曾经并将继续具有巨大的潜力来革新技术设备的发展。对于通常仅由单层原子组成的低维材料，能够检查其原子结构并了解其如何影响器件性能是至关重要的。透射电子显微镜（TEM）是研究低维材料原子结构的唯一手段之一。直到最近，tem的空间分辨率受到光学成像系统像差的固有限制。然而，像差校正器的发展，相当于一副老花眼镜，可以校正显微镜的一些像差（如散光），使得原子尺度图像的空间分辨率提高了三倍以上。2010年，作为arra资助的NSF-MRI-R2项目的一部分，伊利诺伊大学芝加哥分校获得了一笔赠款，用于获得一架像差校正扫描透射电子显微镜（STEM），该显微镜可以在常规基础上实现单原子分辨率。当前的项目将升级该仪器最关键的部件之一：电子能量损失光谱仪（EELS）。此次升级将影响150多名用户的研究，其中包括伊利诺伊大学芝加哥分校（UIC）的13名共同pi和合作者，以及周边机构和来自世界各地的研究。这一升级的EELS系统的安装极大地提高了UIC相关教师的教学和推广能力，并在中西部中部地区建立了一个卓越的区域中心，为学生和科学家提供无与伦比的TEM仪器。透射电子显微镜（TEM）是研究功能纳米材料和二维材料系统的原子尺度结构-性质关系的重要工具。随着像差校正器和冷场发射电子源的发展，在200kV工作的tem的空间分辨率已达到70 pm，能量分辨率优于350 meV。该项目寻求资金，以升级现有的电子能量损失（EEL）光谱仪上的像差校正冷场发射JEOL ARM200CF STEM/TEM，以更好地服务于伊利诺伊大学芝加哥分校（UIC）的材料科学研究和教育。拟议的升级将用Gatan双EELS量子光谱成像滤波器取代目前的Gatan Enfina光谱仪，这是一种先进的、高速的、高灵敏度的光谱仪，具有更高的能量分辨率。在这样做的过程中，pi将显著提高i)由于在成像滤波器的末端存在相机，因此在EEL光谱成像期间可实现的空间分辨率；ii)由于采集电子设备和提高的采集效率，提高了单个EEL光谱或整个光谱图像的采集速度；iii)由于更高稳定性的电子设备和更高效的采集相机，能量分辨率和范围。对中西部TEM社区和当地教育资源的广泛影响将是显著的。升级后的仪器将继续由UIC的研究资源中心运营，该中心是先进TEM教学和培训的卓越中心。UIC的教师将进一步利用该工具与周边学术机构和工业实验室的团队以及来自世界各地的合作者建立强大的协作互动，以最大限度地扩大UIC多样化学生群体的培训和研究机会。

Low dimensional materials had, and continue to have, a huge potential to revolutionize the development of technological devices. For low dimensional materials, which often consist of just a single layer of atoms, it is essential to be able to examine their atomic structure and develop an understanding of how it influences the device properties. Transmission electron microscopy (TEM) is one of the only means by which atomic structures of low dimensional materials can be studied. Until recently, the spatial resolution of TEMs was inherently limited by the aberrations of the optical imaging system. However, the development of aberration correctors, the equivalent of a pair of reading glasses, which correct for some of the microscope's aberrations (e.g. astigmatism), has allowed improvement of spatial resolution of atomic-scale images by more than a factor of three. In 2010, as part of the ARRA-funded NSF-MRI-R2 program, the University of Illinois at Chicago was awarded a grant to acquire an aberration-corrected scanning transmission electron microscope (STEM), which can achieve single atom resolution on a routine basis. This current project will upgrade one of the most crucial components of the this instrument: the electron energy-loss spectrometer (EELS). The upgrade will impact the research of the more than 150 users, including the 13 co-PIs and collaborators at the University of Illinois at Chicago (UIC), surrounding institutions and from around the world. The installation of this upgraded EELS system dramatically improves the teaching and outreach capabilities of the involved faculty at UIC, and establishes a regional center of excellence in a central Midwest location providing unparalleled TEM instrumentation access to students and scientist Transmission electron microscopy (TEM) is an essential tool in the study of the atomic-scale structure-property relationships of functional nano-materials and 2-dimensional materials systems. With the development of aberration correctors and cold-field emission electron sources, the spatial resolution of TEMs operated at 200kV has now reached 70 pm with an energy resolution of better than 350 meV. This project seeks funding to upgrade the existing electron energy-loss (EEL) spectrometer on the aberration-corrected cold field-emission JEOL ARM200CF STEM/TEM to better serve the materials science research and education at the University of Illinois - Chicago (UIC). The proposed upgrade will replace the current Gatan Enfina spectrometer with a Gatan Dual EELS Quantum spectrum-imaging filter, an advanced, high-speed, high-sensitivity spectrometer with increased energy resolution. In doing so, the PIs will dramatically improve i) the attainable spatial resolution during EEL spectrum imaging due to the presence of a camera at the end of the imaging filter; ii) the acquisition speed of individual EEL spectra or entire spectrum images due to the acquisition electronics and increased collection efficiency; and iii) the energy resolution and range due to higher-stability electronics and more efficient acquisition cameras. The broader impacts on the TEM community in the Midwest and the local educational resources will be significant. The upgraded instrument will continue to be operated by UIC's Research Resources Center, a center of excellence for teaching and training of advanced TEM. The faculty at UIC will further use the instrument to develop strong collaborative interactions with groups at surrounding academic institutions and industrial laboratories, as well as collaborators from around the world to maximizing the outreach opportunities for training and research of UIC's diverse student body.