Acquisition of a Low Energy Electron Microscope

低能电子显微镜（LEEM）是一种最近可用的材料表征技术，它允许低能电子探测固体的外层。利用LEEM首先可以成像表面形貌，其次可以从近表面结构的周期性观察衍射，第三可以利用光电子成像，从而探测电子结构的空间变化。这些仪器非常适合于从高温到低于室温范围内的样品检测。现场动力学研究提供了特殊的机会，不仅可以实时观察物体，还可以观察表面现象。由于LEEM仪器在超高真空的极限下工作，表面可以保持数小时不受污染，因此可以访问表面结构和反应的动力学。另一项重要的资产是在样品附近的访问端口的可用性，这些端口可以容纳分子束源，以便在观测之前或期间进行外轴生长。提供这些强大功能组合的商用机器现在才开始可用。因此，将LEEM仪器专门应用于材料研究界感兴趣的材料研究问题的时机已经成熟。该机器将用于研究在生长、氧化或精确定制样品表面的其他反应过程中发生的动态阶梯流动过程的实时成像。我们对材料本身的关注承诺记录和系统化各种晶体类型的这种类型的信息，除了发现通常奖励这种类型的探索性研究的新工艺。这（LEEM）将被放置在伊利诺伊大学震中，一个中央设施，致力于晶体生长和金属，陶瓷和半导体的表面加工。

9503490 Flynn The Low Energy Electron Microscope (LEEM) is a recently- available materials characterization technique which allows low energy electrons to probe the outer layers of a solid. With LEEM it is possible first to image surface topography, second to observe diffraction from the periodicities of the near-surface structure, and third to image using photoelectrons and thus probe the spatial variation of electronic structure. These instruments are very well adapted to the examination of samples through the range from high temperature to below room temperature. In situ dynamical studies offer special opportunities to view in real time not only bulk but also surface phenomena. As LEEM instruments operate in the limit of ultrahigh vacuum where surfaces remain uncontaminated for many hours, the dynamics of surface structure and reactions thus become accessible. A further major asset is the availability in the vicinity of the sample of access ports that can house molecular beam sources for eptiaxial growth conducted before or during observations. Commercial machines which offer these powerful combinations of capabilities are just now becoming available. The time is therefore ripe for the dedicated application of a LEEM instrument to materials research problems of critical interest tot the materials research community. This machine will be used to study the real time imaging of kinetic step flow processes that occur during growth, oxidation or other reaction on the surfaces of precisely tailored samples. Our focus on the materials themselves promises to document and systematize information of this type for a variety of crystal types, in addition to the discoveries of new processes that typically rewards this type of exploratory research. This (LEEM) will be placed in the University of Illinois EpiCenter, a central facility dedicated to the crystal growth and surface processes of metals, ceramics, and semiconductors.