Classical ultraviolet photoelectron spectroscopy of polymers

Although X-ray photoelectron spectroscopy of polymers was well established by Clark and coworkers in the 1970s, ultraviolet photoelectron spectroscopy of polymer films, was developed later. Previous to the 1970s, the first attempts to use ultraviolet light on polymer films took the form of appearance potential (valence band edge) measurements. Only some years later could the full valence band region of thin polymer films, including insulating polymers, semiconducting polymers and electrically conducting polymers. The development of what might be termed “classical ultraviolet photoelectron spectroscopy” of polymer films may be loosely based upon a variety of issues, including adapting thin polymer film technology to ultra high vacuum studies, the widespread use of helium resonance lamps for studies of solid surfaces, the combined advent of practical and sufficient theoretical–computational methods. The advent of, and the use of, easily available synchrotron radiation for multi-photon spectroscopies, nominally in the area of the near UV, is not included in the term “classical”. At the same time, electrically conducting polymers were discovered, leading to applications of the corresponding semiconducting polymers, which added technologically driven emphasis to this development of ultraviolet photoelectron spectroscopy for polymer materials. This paper traces a limited number of highlights in the evolution of ultraviolet photoelectron spectroscopy of polymers, from the 1970s through to 2008. Also, since this issue is dedicated to Prof. Kazuhiko Seki, who has been a friend and competitor for over two decades, the author relies on some of Prof. Seki's earlier research, unpublished, on who-did-what-first. Prof. Seki's own contributions to the field, however, are discussed in other articles in this issue.     

Co:BaTiO3/Si(100)纳米复合薄膜制备、微结构及其紫外光电子能谱研究

采用脉冲激光气相沉积(PLD)方法,在Si(100)晶面上制备了Co:BaTiO₃纳米复合薄膜.采用X射线衍射(XRD)结合透射电镜(TEM)方法研究了两种厚度Co:BaTiO₃纳米复合薄膜的晶体结构,当薄膜厚度约为30 nm时,薄膜为单一择优取向;当薄膜厚度约为100nm时,薄膜呈多晶结构.原子力显微镜(AFM)分析表明,当膜厚为30nm时,薄膜呈现明显的方形晶粒.采用紫外光电子能谱(UPS)研究了Co的价态和Co:BaTiO₃纳米复合薄 关键词： 3')" href="#">BaTiO₃ 纳米复合薄膜 紫外光电子能谱     

Electronic structure of substituted bicycloheptanones (camphors)

He I photoelectron spectra of some camphor derivatives have been recorded and are assigned on the basis of correlations with the spectra of related molecules. The spectra reported in this work together with those reported previously form a camphor database for study of electronic structure interactions between functional groups themselves and between groups and the bicycloalkane skeleton. The unsymmetrical camphor skeleton is found to be a poor relay for σ−π interactions.     

多晶铑表面上碳氧共存体系的研究

用紫外光电子能谱（ＵＰＳ）和俄歇电子能谱（ＡＥＳ）对碳氧共存的多晶铑表面及ＣＯ、Ｏ_２、Ｃ_２Ｈ_４在该表面上的吸附进行了研究，发现铑表面上共存的表面碳和表面氧存在相互作用，由于表面氧的存在，外来吸附物如ＣＯ、Ｏ_２、Ｃ_２Ｈ_４等可以覆盖在表面碳上面，使表面碳占据表面位抑制其它物种吸附的屏蔽效应消失。该表面具有氧化性，可以把吸附的乙烯氧化。     

Crystallographic study of interaction between adspecies on metal surfaces

The interaction among adsorbed atoms and molecules (adspecies) on metal surfaces plays a decisive role in catalytic reactions. Such interaction may cause structural changes of the local adsorption geometry which, together with spectroscopic and energetic data, may afford useful physical and chemical insights into the basic mechanisms of surface processes. When the adsorption geometry of a single adspecies is considered as a function of coverage, a deeper understanding of the nature of the adsorbate-substrate bonding can be obtained. Depending on the adsorbate coverage, the magnitude of adsorbate-induced relaxations and reconstructions vary widely. Occasionally, chemisorption systems transform gradually into adsorbate-substrate compounds, such as oxides, nitrides, hydrides, and sulfides. For the case of adsorption of different adspecies, coadsorption, structural data can make a vital contribution to our understanding of reaction intermediates, the promotion effect in heterogeneously catalyzed reactions, and the formation of ultra-thin compound films.     

噻吩多烯基丙二酸二甲酯类化合物的气相研究

气相Hel紫外光电子能谱（UPS）能从孤立分子的分子轨道特性给出研究分子的电子结构、构型、构象以及成键特性等的大量信息．为此，我们开展了分子体系中带有数基为阻断基团的三岔共把系列化合物的＊PS研究【’－‘］其各自分子轨道的特性提供了它们遵守同东线性规律的实验和理论依据．本文报导唾吩多烯基雨二酸二甲酯类化合物（1）、（2）、（3）的UPS研究·结果表明，它们遵从同系线性规律；同时从分子轨道的原子特性论证了文献间推证的一C00CH3基团的结构效应．这些尚未见文献报导．1实验和计算文献则报导了这类化合物的合成·研究化…     

Lithium adsorption on TiO2: studies with electron spectroscopies (MIES and UPS)

The adsorption of lithium atoms on rutile TiO₂(110) single crystals was studied with metastable‐induced electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy (UPS(HeI)) between 130 K and room temperature. Some auxiliary measurements on W(110) required for data interpretation are also reported. At 130 K ionic adsorption at titania prevails up to 0.3 monolayer equivalents (MLE) as judged from the weak Li(2s) emission in MIES for these exposures. The reduction of the Ti⁴⁺ cation is manifested by the growth of an occupied bandgap state in UPS: the alkali s‐electron is transferred to a near‐surface cation, thereby reducing it to Ti³⁺ 3d. The transfer of the s‐electron is responsible for the observed work function decrease up to ～0.5 MLE coverage. From the analysis of the UPS Ti³⁺ 3d signal, as well as from the Li(2s) emission, it is concluded that the degree of ionicity of the adsorbed Li decreases from 100% at 0.3 MLE to 40% at 0.7 MLE. Above 0.5 MLE the MIES spectra are dominated by an Li(2s)‐induced peak indicating the presence of Li with an at least partially filled 2s orbital. At temperatures above 160 K this peak is almost absent. Excluding Li desorption at these temperatures, we suggest that Li moves into or below the rutile TiO₂(110) surface above 160 K. Lithium insertion into the surface and intercalation are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

CH3（ad）在清洁及预吸附氧Pd（100）表面的热脱附性能

用高分辨电子能量损失谱，热脱附谱，紫外光电子能谱研究了ＣＨ３在清洁及预吸附氧Ｐｄ表面上的热稳定性。ＣＨ３由ＣＨ３Ｉ在Ｐｄ表面的热分解来产生。ＣＨ３Ｉ的ＨＲＥＥＬＳ表明，ＣＨ３中的Ｃ－Ｈ键近似与表面平行，ＣＨ３Ｉ在Ｐｄ表面低于１１０Ｋ时已裂解为ＣＨ３和Ｉ，大量的ＣＨ３在２００－２１０Ｋ的温度范围内的Ｈ结合并以ＣＨ４的形式脱附，但在氧改性表面，ＣＨ４脱附的温度范围变宽，脱附温度有所提高，可能是由于表面     

Synthesis and structural characterization of amorphous nano-sized SiBONC ceramic powders via polymer pyrolysis

SiBONC ceramic powders have been prepared via a polymer pyrolysis route using silicon tetrachloride (SiCl₄), benzaldehyde (PhCHO), boron trichloride (BCl₃) and aniline (PhNH₂) as starting materials. Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were performed to investigate the structural characteristics of the polymer precursor and the ceramic powders. The SiBONC ceramic powders in spherical shape with a mean diameter of 50 nm are amorphous and composed of B-N, Si-O, Si-C, and SiON_x groups. The SiBONC ceramic powders were sintered at 1700 °C to a dense material which still remained amorphous.