Characterization of Alumina Surface Contaminated Sulfur Compounds Studied by Tunneling Spectroscopy

通过隧道光谱研究氧化铝表面污染的硫化合物的表征

• 批准号: 02650545
• 负责人: KAMATA Satsuo
• 金额: $ 1.22万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650545/
• 关键词: Inelastic electron tunneling spectroscopy; Vibration spectra; Surface analysis; Alumina Surface; Organic sulfur compounds; Iron surface; Organic phosphorous compounds; Esters; 金属酸化物; アルミナ

Analyses of alumina surfaces were investigated by inelastic electron tunneling spectroscopy. The tunneling spectra of adsorbed species for organic thioacids, thioureas, thioamides and esters onto the alumina, and of coated silicon or metal film were measured by using Al/alumina(sample or film)/Pb tunneling junction. The following results were obtained from the analysis of vibration spectra.(1)On the clean alumina surfaces, there were many OH-groups, both free and hydrogen bonded, and a few aluminum cations, i. e., Lewis' acid points.(2)Methane and benzen sulfonic acids were adsorbed as sulfonic ions onto alumina surfaces by reaction with surface OH groups. Thioureas and thioamides were found to be adsorbed on the surface by the interaction between the nitrogen atoms of these molecules and Al^+.(3)The analysis of vibration spectra for alkyl benzensulfonates and alkyl phosphites indicated that these esters were decomposed by their reaction with OH groups producing sulfonate and phosphonate ions on aluminum ion, perpendicularly. On the other hand, alkyl carboxylates were found to have two decomposition processes. One is the severing of the bond between the alkyl group and oxygen in the ester molecule, producing alkoxide ions which were adsorbed on the alumina surface. The other is the severing of the bond between the alkyl group and oxygen in the esters ; the carboxylate ions produced were adsorbed on the surface.(4)The evaporated silicon thin film on alumina was found to form many SiH_X on the surface. Inelastic electron tunneling spectra for copper or iron thin films on alumina showed that no signals were observed due to the copper or iron metals. This is interesting phenomena in the analysis of adsorbed compounds onto metal surfaces.

通过非弹性电子隧道光谱研究了氧化铝表面的分析。利用Al/氧化铝（样品或薄膜）/Pb隧道结测量了氧化铝上有机硫代酸、硫脲、硫代酰胺和酯的吸附物质以及涂覆的硅或金属薄膜的隧道光谱。振动谱分析得到以下结果：(1)洁净的氧化铝表面存在大量的游离和氢键的OH基团，以及少量的铝阳离子，即。 (2)通过与表面OH基团反应，甲烷和苯磺酸以磺酸离子的形式吸附到氧化铝表面上。发现硫脲和硫代酰胺通过这些分子中的氮原子与Al^+之间的相互作用而吸附在表面。(3)烷基苯磺酸酯和烷基亚磷酸酯的振动光谱分析表明这些酯通过与Al^+反应而分解。 OH基团垂直于铝离子产生磺酸根和膦酸根离子。另一方面，发现烷基羧酸盐有两个分解过程。一是酯分子中的烷基与氧之间的键断裂，产生醇盐离子，吸附在氧化铝表面。另一种是酯中烷基与氧之间的键断裂； (4)氧化铝上蒸镀的硅薄膜在表面形成了许多SiH_X。氧化铝上的铜或铁薄膜的非弹性电子隧道光谱表明，没有观察到由于铜或铁金属而产生的信号。在分析金属表面吸附的化合物时，这是一个有趣的现象。