Electron Spectroscopic Studies of the Electronic and Geometric Structure of, and Chemisorption on, Transition Metal Oxide Surfaces

在过去的几年里，表面科学实验室在 耶鲁大学已经成为世界上最重要的研究机构 氧化物基本性质研究中心 表面。 亨利克教授的方法是用单晶 样品，制备和研究在一个真空环境 或在受控的化学吸附条件下， 它们的几何结构和电子结构， 表面灵敏电子光谱技术。 特别 已经注意到过渡金属氧化物，其 阳离子可以有几种不同的价态 取决于它们的配体环境;这些氧化物是 催化和表面化学中最重要的。 在几乎完美的真空解理表面上进行的测量是一种 必要的起点，特别是与 理论计算。 然而，他的主要兴趣是 表面缺陷的性质及其与 吸附分子 表面缺陷已被证明是 几乎所有氧化物上的化学吸附活性位点， 研究表明，几乎完美的表面相对 惰性 亨利克教授在这里提出了一项为期三年的研究 该计划包括最富有成效的 目前正在进行的研究领域和几个 新的方向，将解决一些重要的问题， 迄今为止的研究还没有找到答案。 空电子 氧化物表面上的状态将通过使用反 光电子能谱，以及新获得的高分辨率 电子能量损失谱仪将用于研究 具有催化作用的分子间相互作用的微妙之处 与氧化物。 与IBM沃森研究中心的合作 中心将使用扫描隧道显微镜来确定 完美和缺陷氧化物表面的几何形状，并测量 它们的满电子能级和空电子能级的光谱。

During the past few years the Surface Science Laboratory at Yale has become established as the world's foremost research center for the study of the fundamental properties of oxide surfaces. Professor Henrich's approach is to use single crystal samples, prepared and studied in an ultrahigh vacuum environment or under controlled chemisorption conditions, and to measure their geometric and electronic structure by using a wide range of surface sensitive electron spectroscopic techniques. Particular attention has been given to the transition metal oxides, whose cations can have any of several different valence states depending upon their ligand environment; these oxides are the most important ones in catalysis and surface chemistry. Measurements on nearly perfect, vacuum cleaved surfaces are a necessary starting point, particularly for comparison with theoretical calculations. However, his primary interest is in the properties of surface defects and their interaction with adsorbed molecules. Surface defects have been shown to be the active sites for chemisorption on almost all oxides that have been studied, with nearly perfect surfaces being relatively inert. Professor Henrich proposes here a three-year research program consisting both of a continuation of the most productive research areas that are currently being pursued and of several new directions that will address some of the important questions that research to date has left unanswered. Empty electronic states on oxide surfaces will be examined by using inverse photoelectron spectroscopy, and a newly acquired high resolution electron energy loss spectrometer will be used to study the subtleties of the interaction of molecules of catalytic interest with oxides. A collaborative effort with the IBM Watson Research Center will use scanning tunneling microscopy to determine the geometry of both perfect and defect oxide surfaces and to measure the spectra of their filled and empty electronic levels.