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拥有巨大的潜力，使技术设备的发展发生革命性的变化。对于通常只由一层原子层组成的低维材料，能够研究它们的原子结构并了解它如何影响器件性能是至关重要的。透射电子显微镜是研究低维材料原子结构的唯一手段之一。直到最近，由于光学成像系统的像差，正电子显微镜的空间分辨率一直受到限制。然而，像差校正器的发展，相当于一副老花镜，可以校正显微镜的一些像差(例如散光)，使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计划的一部分，芝加哥伊利诺伊大学获得了一项赠款，获得了一台像差校正扫描透射电子显微镜(STEM)，它可以在常规基础上实现单原子分辨率。目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)、周围机构和来自世界各地的13名合作PI和合作者。这个升级的EELS系统的安装极大地提高了UIC相关教员的教学和推广能力，并在中西部中部建立了一个区域卓越中心，为学生和科学家提供无与伦比的透射电子显微镜仪器。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-性质关系的基本工具。随着像差校正器和冷场发射电子源的发展，目前工作在200kVTEMS的空间分辨率已达70 pm，能量分辨率优于350 meV。该项目寻求资金来升级JEOL ARM200CF STEM/TEM上的现有电子能量损失(EEL)能谱仪，以便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 Dual Eels量子光谱成像滤光片取代目前的Gatan Enfina光谱仪，这是一种先进的、高速、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)由于成像滤光片末端存在摄像头而在鳗鱼光谱成像过程中可获得的空间分辨率；ii)由于采集电子设备和更高的采集效率而导致单个鳗鱼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而提高能量分辨率和范围。这将对中西部的TM社区和当地的教育资源产生更广泛的影响。升级后的仪器将继续由UIC的研究资源中心运营，该中心是先进瞬变电磁教学和培训的卓越中心。UIC的教职员工将进一步利用该工具与周边学术机构和工业实验室的团体以及来自世界各地的合作者建立强有力的协作互动，以最大限度地扩大UIC多样化学生群体的培训和研究的外展机会。

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.