Thesis (Ph. D.)--Princeton University, 1932.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 189-196).

Thesis (Ph. D. in Chemistry)--University of California, Berkeley, Sept. 1957. / Includes bibliographical references (leaves 107-109).

Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Science. / Microfiche copy available in Archives and Science. / Bibliography: leaves 80-84. / M.S.

As another important features in VEELS, the plasmon excitations (including the volume plasmon and surface/interfacial plasmon) are also utilized to identify different phases and multi compositions within materials. The microstructure and electronic structure evolution of silicon-rich oxide (SRO) films as a function of the annealing temperature are investigated using TEM and VEELS. The as-deposited SiO film is found to be a single phase with only single volume plasmon presents in VEEL spectrum and almost no interfacial plasmon is observed. After the annealing (Tanneal>400°C), it begins to decomposite into Si and SiO2 and the single phase changed into cluster/matrix nanocomposites where the interfacial plasmon appears. The Si duster size and its concentration increase as the annealing temperature increases. / Firstly, the applications of VEELS in investigating the electronic structures of ZnO nanowires with different diameter and surface shapes are demonstrated. Using the momentum transferred technique, one of the interband transitions with dipole-forbidden nature is identified. Several size dependent features are found on the interband transitions and plasmon oscillations of ZnO nanowires with small diameter and circular cross section, which are mainly due to the large surface to volume ratio and existence of Oxygen dangling bonds on those ZnO wires. / Further explorations on the electronic structure in the vicinity of band gap are carried out for the ZnO nanowires doped with different dopants (Co, Er, Yb) and different dopant concentrations. In order to obtain trustworthy information in the very low energy range of VEELS a narrow zero loss peak and elimination of Cerenkov effect and surface losses are necessary, which can be realized by incorporation of the gun monochromator in the TEM and taking spectrum at a momentum transfer slightly greater than zero. Band tail states (∼2-3.3 eV) are found to be generated in the ZnO nanowires after the ion implantation and their density of states increase with the ion fluence increases. The partially removal of those defect states by the Oxygen annealing is also observed in VEELS. On the other hand, interesting mid-gap state(s), which is dopant-sensitive (as it is only observed in the rare earth (Er and Yb) doped ZnO nanowires, but not in the Co-doped ones), does not show obvious change after the O annealing. The impact of these electronic structure changes on the material properties are also discussed. / In the end of the thesis, some of the practical limitations and contradictories on the energy resolution (DeltaE), spatial resolution (Delta x), and the momentum resolution (Deltaq) when carrying out the various VEELS study are summarized. The compromise made among these resolution limits is also discussed. / In this work, the important experimental parameters and appropriate data processing methods to generate trustworthy data are discussed. Based on that, three material systems, i.e., pure ZnO nanowires, doped ZnO nanowires, and Si/SiO/SiO2 composite films are investigated. Various information on the material microstructure/electronic structure is interpreted using the VEELS data. / The valence-electron energy-loss spectroscopy (VEELS) contains information on the electronic structures of materials, including the band gap the single-electron interband transitions and the plasmon oscillations. When operating in transmission electron microscope (TEM), the excellent spatial resolution enables the VEELS not only exploring the local electronic structures of individual low dimensional nanostructured materials, but also building up correlations between the electronic structure and microstructure. In addition, the capability in carrying out the momentum transfer dependent study in VEELS allows the investigation on the dispersion of plasmons and single electron excitations in the momentum space. The optically forbidden transitions, which are not allowed in conventional optical method, can also be excited at high momentum transfer values using VEELS. / Wang, Juan = 價電子能量損失譜在低維納米材料中的應用 / 王娟. / "September 2007." / Adviser: Li Quan. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1267. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 122-133). / 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. / Abstract in English and Chinese. / School code: 1307. / Wang, Juan = Jia dian zi neng liang sun shi pu zai di wei na mi cai liao zhong de ying yong / Wang Juan.

This thesis presents a series of electron impact ionization measurements on the gas phase targets of argon and krypton. The (e,2e) coincidence technique has been employed to measure the triple differential cross section (TDCS) using a new coincidence spectrometer designed to operate in the low energy regime (2 to 5 times the ionization energy) and in the coplanar geometry. The spectrometer is a conventional device utilizing a non-energy selected electron gun and two 1800 hemispherical electron analysers fitted with channel electron multipliers for detection of the outgoing electrons. A series of TDCS measurements were performed on the 3s inner-valence and 3p valence orbitals of argon employing coplanar asymmetric kinematics. Measurements for both orbitals were performed at an incident energy of 113.5 eV, ejected energies of 10, 7.5, 5 and 2 eV and a scattering angle of -15°. The energy of the scattered electron in each case was chosen to satis~' energy conservation and is dependent on the ionization energies of the different orbitals. The experimental cross sections are compared to theoretical TDCS calculations using the distorted wave Born approximation (DWBA) and variations of the DWBA in an attempt to investigate the role that post collisional interaction (PCI), polarization and electron exchange play in describing the TDCS in the low energy regime. To further extend this analysis, a series of TDCS measurements were performed on the 3s and 4s. orbitals of argon and krypton, respectively, employing coplanar symmetric kinematics. Measurements were performed for the 3s orbital at outgoing energies of 50, 20, 10 and 4eV and for the 4s orbital at outgoing energies of 85, 50, 20 and 10 eV. The kinematics were chosen to coincide with several of the (e,2e) measurements made in the same geometry on the 3p orbital of argon by Rouvellou et al (1998). The experimental results were again compared to a DWBA calculation and similar variations to those employed for the asymmetric measurements.

Thesis (Ph.D.)--McMaster University (Canada), 1991. / Source: Dissertation Abstracts International, Volume: 53-01, Section: B, page: 0503. Supervisor: I. D. Brown.

The field of organic electronics, in which -conjugated, organic molecules and polymers are used as the active components (e.g., semiconductor, light emitter/harvester, etc.), has lead to a number a number of key technological developments that have been founded within fundamental research disciplines. In the Dissertation that follows, the research involves the use of quantum-chemical techniques to elucidate fundamental aspects of both intermolecular and intramolecular electron-transfer processes in organic, -conjugated molecules. The Dissertation begins with an introduction and brief review of organic molecular systems used as electron-transport semiconducting materials in device applications and/or in the fundamental studies of intramolecular mixed-valence processes. This introductory material is then followed by a brief review of the electronic-structure methods (e.g., Hartree-Fock theory and Density Functional Theory) and electron-transfer theory (i.e., semiclassical Marcus theory) employed throughout the investigations. The next three Chapters deal with investigations related to the characterization of non-rigid, -conjugated molecular systems that have amorphous solid-state properties used as the electron-transport layer in organic electronic and optoelectronic devices. Chapters 3 and 4 involve studies of silole- (silacyclopentadiene)-based materials that possess attractive electronic and optical properties in the solid state. Chapter 5 offers a preliminary study of dioxaborine-based molecular structures as electron-transport systems. In Chapters 6 8, the focus of the work shifts to investigations of organic mixed-valence systems. Chapter 6 centers on the examination of tetraanisylarylenediamine systems where the inter-redox site distances are approximately equal throughout the series. Chapter 7 examines the bridge-length dependence of the geometric structure, charge-(de)localization, and electronic coupling for a series of vinylene- and phenylene-vinylene-bridged bis-dianisylamines. In Chapter 8, the role of symmetric vibrations in the delocalization of the excess charge is studied in a dioxaborine radical-anion and a series of radical-cation bridged-bisdimethylamines. Finally, Chapter 9 provides a synopsis of the work and goals for future consideration.