Doctoral theses
Current Record: 1984 of 2491
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Identifier |
uch.physics.phd//2002remediakis |
Title |
First - Principles Studies of Solid Surfaces: Pure and C-alloyed Si(100) and NO chemisorption on MoO3(010) |
Alternative Title |
Μελέτες στερεών επιφανειών από πρώτες αρχές: Si(100), Si(100) εμπλουτισμένη με C,και προσρόφηση ΝΟ στην MoO3(010) |
Author
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Ρεμεδιάκης, Ιωάννης Ν
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Thesis advisor
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Κελίρης, Παντελής
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Abstract |
The present Dissertation deals with modeling of representative solid surfaces and surface processes using fist-principles methods. We first present a generalization of Density Functional Theory (DFT) to include excited states, as the original formulatioased on ground-state properties of the electron gas. This allows us to give a detailed review of DFT, which is used throughout the Thesis for exploring properties of the surfaces , and to demonstrate a simple but efficient method for calculating band gaps of semiconductors. The first surface under consideration is Si(100), a simple system of enormous technological interest. Our study includes detailed analysis of the chemical bonding, energetics and electronic structure; this system is used as a framework to present in detail theoretical tools used in studies of surface phenomena, the most important among them being simulation of Scanning Tunneling Microscope (STM), which allows direct comparison to experimental observations. We next study C-alloyed Si(100), a surface used in many cases as an initial stage for growth of complicated structures, such as SiGe quantum dots and B-doped SiGe superlattices, used in various microelectronic applications. For the case of low C content, we reveal for the first time an impressive long-range order in the C distribution, a prediction that has not yet been tested experimentally. Fir high C content of the system, we find the structures that can account for the observed STM images, and discuss their nature. The Dissertation concludes by a study related to catalysis. We study various geometriwes of NO adsorption on MoO3(010), a widely used surface for the catalytic reduction of NO. We propose that the reduction is a non-dissociative process, and that it happens through formation of a dinitrosyl (NO2)) on an exposed Mo atom of the surface.
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Language |
English |
Issue date |
2002-11-01 |
Date available |
2002-04-04 |
Collection
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School/Department--School of Sciences and Engineering--Department of Physics--Doctoral theses
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Type of Work--Doctoral theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/a/7/f/metadata-dlib-2002remediakis.tkl
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Views |
687 |