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通过扫描光发射成像和光谱显微镜表征微材料和纳米材料的最新成就
Recent achievement in characterization of micro- and nano-materials by scanning photoemission imaging and spectromicroscopy |
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| 课程网址: |
http://videolectures.net/slonano07_gregoratti_rac/
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| 主讲教师: |
Luca Gregoratti
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| 开课单位: |
约瑟夫·斯特凡学院
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| 开课时间: |
2008-02-12
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| 课程语种: |
英语
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| 中文简介: |
相对于其他光电子显微镜技术，扫描光发射显微镜（SPEM）使用最直接的方法进行光电子光谱显微镜检查，即使用小型聚焦光子探针照亮表面。 Elettra同步加速器光源上的SPEM可以两种模式运行：成像和光谱。在第一模式中，通过相对于聚焦的光子束同步扫描样品并收集具有选定动能的光电子来映射样品表面。第二种模式是来自微点的光电子能谱。 Elettra的ESCAmicroscopy光束线上的SPEM的横向分辨率为150 nm；整体能量分辨率现在优于200 meV。在测量过程中，样品可以加热，冷却（液态N2）并偏置。光束线向公共和私人研究界开放；每年有两次关于实验的征集建议，以及针对特定项目进行专门合作的可能性。将介绍在纳米和微结构材料的化学，物理和电子表征方面的一些最新成就，以概述这种强大技术的功能。将介绍金属吸附剂的相互作用，多壁碳纳米管，半导体纳米管和金属纳米管的氧化和支撑性能，表明如何通过SPEM监测动力学现象，例如沿纳米管表面的质量传输。样品的特殊设计允许研究直径低至60nm的单个纳米管。还将介绍形态复杂的3D半导体结构的组成和电子性质的研究。近年来，已经与国际公司建立了重要的产业合作关系。第一个例子将报告对有机发光器件（OLED）上发生的降解过程的研究。将比较两种在环境气氛下运行并在超高真空下生长和运行的OLED的结果。另一个例子将说明在操作条件下固体氧化物燃料电池阴极表面的化学特征。讨论了元素分布及其在偏压下的变化以及阴极电化学活化的观察和解释。最后，将概述操作原理对X射线光电子显微镜的应用范围的限制，并结合未来的发展，使人们能够研究毫巴甚至环境压力下的材料。
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| 课程简介: |
With respect to the other photoelectron microscopy techniques a Scanning PhotoEmission Microscope (SPEM) uses the most direct approach to photoelectron spectromicroscopy which is the use of a small focused photon probe to illuminate the surface. The SPEM at the Elettra synchrotron light source can operate in two modes: imaging and spectroscopy. In the first mode the sample surface is mapped by synchronized-scanning the sample with respect to the focused photon beam and collecting photoelectrons with a selected kinetic energy. The second mode is photoelectron spectroscopy from a microspot. The SPEM on the ESCAmicroscopy beamline at Elettra has a lateral resolution of 150 nm; and an overall energy resolution which is now better than 200 meV. Samples can be heated, cooled (liquid N2) and biased during the measurements. The beamline is open to the public and private research community; two call for proposals of experiment are available per year together with the possibility of dedicated collaborations on specific projects. Some recent achievements in the chemical, physical and electronic characterization of nano- and micro-structured materials will be presented providing an overview of the capabilities of this powerful technique. Metallic adsorbate interaction, oxidation and supporting properties of multiwall carbon, semiconducting and metal-based nanotubes will be presented, showing how even dynamic phenomena such as mass transport along the nanotube surface can be monitored by the SPEM. A special design of the samples allows for the investigation of single nanotubes with diameter down to 60nm. The study of compositional and electronic properties of morphological complex 3D semiconducting structures will be presented as well. Important industrial collaborations with international companies have been established in last years. A first example will report on the study of the degradation processes occurring on Organic Light Emitting Devices (OLEDs). Results on both OLEDs operated in ambient atmosphere and grown and operated in ultra-high-vacuum will be compared. Another example will illustrate the chemical characterization of the cathode surfaces of Solid Oxide Fuel Cells under operating conditions; the elemental distribution and its change under biasing and the observation and explanation of the cathode electrochemical activation have been addressed. Finally an overview of the limits in the applications of the x-ray photoelectron microscopes imposed by the operation principles will be given together with the future developments allowing the investigation of materials at mbar and even ambient pressure.
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| 关 键 词: |
成像; 光谱; 光电子显微镜技术
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| 课程来源: |
视频讲座网
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| 最后编审: |
2019-09-25：yuh
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| 阅读次数: |
22
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