Ge(100) has atomic and electronic structures quite similar to those of Si(100). As a comparison, we have studied the oxidation of Ge(100) surface. Our comparison of the initial oxidation of Ge(100) with that of Si(100) by molecular oxygen shows that the precursor-mediate mechanism and direct adsorption mechanism are common to both systems. (Abstract shortened by UMI.) / It is often been argued that a direct [2+2] addition of unsaturated hydrocarbons to the Si-Si dimer is symmetry forbidden, according to the Woodward-Hoffmann rule. This view is now challenged by our calculations on the reaction path for a concerted [2+2] addition of C2H4 to a Si-Si dimer on Si(100), which identifies a barrier of only ∼0.1eV. Our analysis shows that this is due to the peculiar feature for a surface reaction, when the HOMO and LUMO bands cross the Fermi level of the substrate, as previously suggested by Hoffmann. It illustrates an important conceptual distinction between a gas phase and a surface reaction. / Many previous theoretical studies on the interaction between O2 and Si(100) have neglected the differences between triplet O2 (ground state) and singlet O2 (excited state), and are thus unable to explain the know experimental observations in surface scattering of O2. We demonstrate that in reality, triplet O2 can also react with Si(100). With our computation results on the potential energy curves of the adsorption of triplet O2 on Si(100) and the adsorption structures along these curves, we can explain the known experimental results. The proper adsorption pathway goes through a shallow physisorption potential well, a small transition state and reaches a molecular adsorption state. There are also some interesting interactions between the potential energy curves of the triplet O2 adsorption and singlet O2 adsorption. / This thesis addresses the basic physics and chemistry of some surface reactions by first-principles methods based on density functional theory. The reaction systems probed by this thesis include the cycloaddition of C2H4 on Si(100), and initial oxidation of Si(100), Ge(100) and Al(111) by molecular oxygen. They are all technologically important systems and yet simple enough for us to study them in details theoretically. Although they have been studied both experimentally and theoretically, our first principles calculations reveal new insights that are contrary to prevalent opinions. / Fan Xiaoli = 从头算法研究研究在硅100, 锗100 和铝111 表面上的反应 / 范晓丽. / "June 2005." / Adviser: Lau Woon-ming Leo. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3854. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Text in English; abstracts in English and Chinese. / School code: 1307. / Fan Xiaoli = Cong tou suan fa yan jiu yan jiu zai gui 100, zhe 100 he lü111 biao mian shang de fan ying / Fan Xiaoli.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_343681 |
| Date | January 2005 |
| Contributors | Fan, Xiaoli, Chinese University of Hong Kong Graduate School. Division of Physics. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xvi, 134 p. : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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