Analysis of Solid Surfaces by Means of Penning Ionization Electron Spectroscopy and High Resolution Electron Energy Loss Spectroscopy

虽然最近固体表面的研究取得了很大的进展，但对表面上发生的反应过程还没有很好的了解。这似乎是因为对最外层有选择性地敏感的表面分析方法没有得到很好的应用。在这项研究中，我们试图发展一种结合PIES(潘宁电离电子能谱)和HREELS(高分辨电子能量损失能谱)的表面分析新方法。PIES选择性地提供固体最外层的电子态信息，而HREELS使我们能够灵敏地探测最外层的原子和分子振动。为了实现上述目的，我们设计并建造了一台仪器，包括LEED(低能电子衍射)、AES(俄歇电子能谱)和UPS(紫外光电子能谱)以及PIES和HREELS的仪器。使用TH…更重要的是，我们研究了清洁的Ni(100)表面和CO在其表面的吸附。用LEED和AES研究了表面的结构和原子组成，用PIES和UPS研究了表面的电子态，用高分辨电子能谱(HREELS)研究了振动态。对馅饼的测量得出了以下结果。在清洁的镍表面上，一个亚稳态氦原子的2S电子转移到镍表面形成一个离子。因此，相应的光谱与INS(离子中和光谱)的光谱相似。另一方面，在被吸附的表面，由于Ni表面被CO原子屏蔽，发生了Penning电离过程。在这种情况下，PIES可以获得吸附表面外暴露的单个轨道的电子分布的直接信息。此外，还利用PIES和UPS对各种有机薄膜的表面进行了表征。已经证实，PIES使我们能够灵敏地检测固体最外表层分子取向和电子态的变化。特别是，最近注意到的LB膜中的分子取向已经被发现即使在由一个到几个单分子层组成的超薄膜的情况下，Pies也可以直接知道。较少

Although much progress has recently been made in the study of solid surfaces, the process of reactions taking place on the surfaces has not been well understood. This seems to be due to the fact that surface-analysis methods which are selectively sensitive to the outermost surface layer have not been well applied. In this study, we tried to develop a new method of surface analysis with the combination of PIES (Penning ionization electron spectroscopy) and HREELS (high resolution electron energy loss spectroscopy). PIES provides information on the electronic state of the outermost surface layer of solid selectively, whereas HREELS enables us to detect atomic and molecular vibrations at the outermost layer sensitively.To achieve the above purpose, we designed and constructed an instrument including the appratuses for LEED (low energy electron diffraction), AES (Auger electron spectroscopy), and UPS (ultraviolet photoelectron spectroscopy) together with those for PIES and HREELS. Using th … More is instrument, we studied surfaces of clean Ni(100) and CO adsorbed on it. The structure and atomic composition of the surfaces were investigated by LEED and AES, the electronic state by PIES and UPS, and the vibrational state was examined by HREELS. The measurements of <He^*> PIES gave the following results. On the clean Ni surface the 2s electon of a metastable helium atom transfers to the Ni surface to form a <He^+> ion. Therefore, the corresponding spectrum is similar to that given by INS (ion neutralization spectroscopy). On the adsorbed surface, on the other hand, Penning ionization process takes place because the Ni surface is shielded by CO atoms. In this case, direct information on the electron distribution of individual orbitals exposed outside the adsorbed surface can be obtained by PIES.In adition to the above study, the characterization of surfaces of various organic thin films was performed by PIES and UPS. It has been confirmed that PIES enables us to detect sensitively the changes in the molecular orientation and electronic state at the outermost surface layer of solid. In particular, the molecular orientation in LB (Langmuir-Blodgett) films noted recently has been found to be directly known by PIES even in the cases of ultra-thin films composed of one to several monolayers. Less