MRI-R2: Acquisition of an X-ray photoelectron spectrometer (XPS)

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。技术摘要：本提案要求为加州大学河滨分校（UCR）购买一台新的分析x射线光电子光谱仪（XPS）提供资金。这将是UCR同类仪器中的第一个。XPS提供了固体表面性质和组成的重要信息，已成为材料科学研究的重要工具。新仪器将从Specs获得，将基于一个金属超高真空（UHV）球形室涡轮泵压至低于10^-9 Torr范围，并将配备一个双阳极x射线源和一个150毫米半球形能量分析仪，一个用于清洁，深度剖面和低能离子散射的离子源，以及用于俄歇电子能谱和补偿样品充电的光栅电子枪和洪射电子枪。它还将包括一个在x， y和z方向上具有线性运动的样品机械手，一个制备室和一个用于快速样品导入的负载锁定系统。该仪器将被设置为远程控制和自动化网络访问，其功能包括所有4个轴（x、y、z和极旋转）的特高压机械手的机动化，x射线源的远程控制接口，用于远程控制喷枪的特殊修改电源，以及SpecsControl软件包，用于全面测量控制，包括样品定位，分析仪控制，x射线源，喷枪和离子源。新的XPS将由UCR的分析化学仪器设备（ACIF）进行维护、操作和管理。它将可供加州大学洛杉矶分校的pi、学生和博士后使用，也可供外部合作伙伴使用，包括一些当地学院（加州州立大学洛杉矶分校、圣贝纳迪诺分校和圣地亚哥分校、拉凡尔恩大学、韦斯特蒙特学院）。摘要：随着新型纳米技术和微电子技术的发展，构成器件的不同元件之间的界面在其总体积中所占的比重越来越大，相应的表面物理和化学对器件性能的影响也越来越大。表面化学在环境问题、生物和分析应用、催化和摩擦学等问题中也很普遍，仅举几例。没有合适的分析工具来研究固体表面，现代材料科学实验室是不完整的。特别是x射线光电子能谱（XPS，也称为ESCA）已经成为材料科学研究中无处不在的工具。XPS依赖于对固体样品在x射线激发下发射的光电子的探测。光电子的近似动能可以转化为电子结合能，并用于确定给定样品的元素组成，以及更精确的测量，以获得围绕特定表面原子的化学环境的信息，特别是它们的氧化状态。光电子产率提供了有关该成分的定量信息。XPS的强大之处在于它依赖于对电子的探测，这使得它对表面非常敏感。大多数典型的分析技术都是基于光子的使用，光子能穿透固体样品的深处，并产生有关样品的信息。相比之下，电子穿过固体的小自由路径允许从最顶层识别信号。结合受控溅射去除材料随着时间的推移，XPS可以设置为提供固体样品的组成和化学性质的深度剖面。在UCR， XPS将用于研究与卟啉分子记忆、石墨烯衍生化、仿生太阳能收集装置、沸石涂层和纳米颗粒、薄膜原子层沉积和催化剂开发等相关的问题。

MRI-R2 0958796ZaeraThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Technical Abstract: This proposal requests funds for the purchase of a new analytical X-ray photoelectron spectrometer (XPS) for the University of California, Riverside (UCR). This will be the first instrument of its type at UCR. XPS provides vital information of the nature and composition of solid surfaces and has become an essential tool in materials science research. The new instrument, to be acquired from Specs, will be based on a mu-metal ultrahigh vacuum (UHV) spherical chamber turbopumped to pressures below the 10^-9 Torr range, and will be equipped with a twin anode X-ray source and a 150 mm hemispherical energy analyzer, an ion source for cleaning, depth-profiling, and low-energy ion scattering, and rasterable and flood electron guns for Auger electron spectroscopy and to compensate for sample charging, respectively. It will also include a sample manipulator with linear movements in the x, y and z directions, a preparation chamber, and a load-lock system for quick sample introduction. The instrument will be set for remote control and automation for cyber access, with capabilities that include motorization of UHV manipulator for all 4 axis (x, y, z and polar rotation), an interface for remote control of the X-ray source, a special modification of the power supply for remote control of the flood gun, and the SpecsControl software package for full measurement control, including sample positioning, analyzer control, X-ray source, flood gun and ion source. The new XPS will be maintained, operated and administered by the Analytical Chemistry Instrumentation Facility (ACIF) of UCR. It will be available for use to PIs, students, and postdoctoral fellows at UCR, and also to outside partners, including a number of local colleges (the California State University Los Angeles, San Bernardino and San Diego campuses, the University of La Verne, Westmont College). Layman Abstract: With the advance of new nanotechnologies and miniaturized microelectronics, the interfaces between the different elements that constitute those devices are becoming a larger part of their total volume, and the corresponding surface physics and chemistry is playing an increasing role in their performance. Surface chemistry is also prevalent in problems related to environmental issues, biological and analytical applications, catalysis, and tribology, to mention only a few. No modern materials-science laboratory is complete nowadays without appropriate analytical tools to study solid surfaces. X-ray photoelectron spectroscopy (XPS, also known as ESCA) in particular has become a ubiquitous tool in materials-science research. XPS relies on the detection of the photoelectrons ejected from solid samples upon excitation with X-rays. The approximate kinetic energies of the photoelectrons can be converted into electron binding energies and used to determine the elemental composition of a given sample, and more accurate measurements to obtain information on the chemical environment surrounding particular surface atoms, in particular their oxidation state. The photoelectron yield provides quantitative information on the composition. The power of XPS is that it relies on the detection of electrons, a fact that renders it quite surface sensitive. Most typical analytical techniques are based on the use of photons, which penetrate deep into solid samples and yield information about the bulk. The small free path of electrons through solids, by contrast, allows for the discrimination of the signal from the topmost layers. Combined with controlled sputtering for the removal of material over time, XPS can be set up to provide a depth profile of the composition and chemical nature of solid samples. At UCR, XPS will be used to study problems related to porphyrin-based molecular memories, grapheme derivatization, biomimetic-based solar harvesting devices, zeolite coatings and nanoparticles, atomic layer deposition of thin films, and catalyst development, among others.