MRI: Acquisition of a 3D Tomographic Atom-Probe Microscope

技术总结：原子探针断层扫描（APT）显微镜是一种新的材料分析仪器，提供了唯一的技术，可以获得三维（3D）断层图像和化学鉴定在原子尺度。它提供了深入了解纳米结构和设备的材料科学，化学，物理和工程中的关键问题。APT显微镜使用来自局部电极的快速脉冲电场从样品中单独去除原子;原子质量由到成像检测器阵列的飞行时间确定。这些3D断层图像可以识别单个原子的元素，甚至同位素。它们能够对纳米线、图案化材料、异质结构和器件中的结构缺陷、掺杂剂、原子结构和组成进行空间映射。直接完全可视化材料的能力是新的，它开辟了一个新的研究和应用范围。该提案要求获得资金，以获得安装在哈佛大学纳米系统中心的3D APT显微镜。APT显微镜将促进物理学家，化学家和设备开发人员与材料科学家之间的合作，允许他们在原子尺度上检查空间调制结构。这一信息对于电子和光子学的纳米级器件尤其重要，其中原子尺度的界面决定了器件的行为。该仪器可用于在原子水平上了解材料的结构，包括复合氧化物半导体，这些半导体有望用于未来的电子产品，太阳能电池和燃料电池。在哈佛大学纳米系统中心安装原子探针断层扫描显微镜将为美国东北地区的研究人员和教育工作者提供直接和开放的访问。 它将为不同的学生群体提供机会。一个创新的教育项目“纳米成像和分析”将使用APT显微镜将研究融入到本科生、研究生和成人的材料科学、物理和化学教学中。外行人总结：为了制作和理解原子尺度的结构，我们必须能够对结构中单个原子的位置进行成像，并识别它们的化学身份。原子探针显微镜是唯一能提供这些信息的技术。三维图像显示原子，不同的颜色可以用来显示它们是哪种元素。 通过创建易于理解的图像，原子探针显微镜将使我们能够制造和理解用于计算，通信，能源生产和医疗的真正小型原子级设备。 该仪器通过使用快速脉冲电场来从样品中去除单个原子-飞行到成像检测器的时间决定了每个原子的质量。这些图像可以识别每个原子的元素，甚至同位素，以及它的位置。原子探针显微镜将安装在哈佛大学纳米系统中心，为美国东北部地区的研究人员和教育工作者提供直接和开放的访问-它将加强对不同学生群体的教育。 这种新仪器将使研究人员能够了解新型电子和光学器件的原子结构，创造新型太阳能电池和燃料电池以缓解国家能源问题，并从原子水平上从根本上研究材料的结构。

Technical Summary: An Atom Probe Tomography (APT) Microscope is a new material analysis instrument that provides the only technique that can obtain both three-dimensional (3D) tomographic images and chemical identification at the atomic scale. It provides insight into key problems in the materials science, chemistry, physics and engineering of nanoscale structures and devices. The APT Microscope uses a rapidly pulsed electric field from a local electrode to remove atoms individually from the sample; the atom mass is determined by the time of flight to an imaging detector array. These 3D tomographic images can identify the element, and even the isotope, of individual atoms. They enable the spatial mapping of structural defects, dopants, and atomic structure and composition in nanowires, patterned materials, heterostructures and devices. The ability to completely visualize a material directly is new, and it opens a new range of investigations and applications. This proposal asks for funds to acquire a 3D APT Microscope for installation in the Center for Nanoscale Systems at Harvard University. The APT Microscope will promote collaborations between physicists, chemists, and device developers with materials scientists by allowing them to examine spatially modulated structures at the atomic scale. This information is particularly important for nanoscale devices for electronics and photonics, where atomic scale interfaces determine the behavior of the device. This instrument can be used to understand the structure of materials at the atomic level, including complex oxide semiconductors that are promising for future electronics, solar cells and fuel cells. The installation of a Atom-Probe Tomography Microscope in the Center for Nanoscale Systems at Harvard University will provide direct and open access for researchers and educators in the Northeast region of the United States. It will provide opportunities for to a diverse population of students. An innovative educational program "Nanoscale Imaging and Analysis" will use the APT Microscope to integrate research into the teaching of materials science, physics and chemistry at the undergraduate, graduate and adult levels.Layman Summary: To make and understand atomic-scale structures, we must be able to both image the location of individual atoms in a structure and identify their chemical identity. Atom Probe Microscopy is the only technique that provides this information. A three-dimensional image displays the atoms, and different colors can be used to show which element they are. By creating images that are easy to understand, an Atom Probe Microscope will allow us to make and understand truly small atomic scale devices for computation, communication, energy production, and medical treatment. The instrument operates by using a rapidly pulsed electric field to remove an individual atom from the sample - the time of flight to the imaging detector determines the mass of each atom. The images can identify the element, and even the isotope, of each atom, as well as its location. The Atom-Probe Microscope will be installed in the Center for Nanoscale Systems at Harvard University, and provide direct and open access for researchers and educators in the Northeast region of the United States - it will enhance the education of a diverse population of students. This new instrument will allow researchers to understand the atomic structure of new electronic and optical devices, create new types of solar cells and fuel cells to ease the national energy problem, and fundamentally study the structure of materials at the atomic level.