Full metadata
Title
First-Principles DFT Study of Imide and Fluoride Analogs of Silicon Oxide, Silicon Oxynitride, and Their Alloys
Description
The potential of designing silicon-based oxide/nitride with new properties through nanostructure and chemical tuning continues to captivate researchers. In this context, while oxynitrides of Si, Ge and Si/Ge are being actively explored, N-rich alternatives to the ubiquitous Si3N4 end member are far less known or studied. Recently, the imide-based Si2N2(NH) was synthesized and found to adopt a crystalline structure analogous to that of Si2N2O. Therefore, in this thesis, a density functional theory (DFT) study of the thermochemistry of Si-N-H compounds including Si2N2(NH) and Si(NH)2 is undertaken, focusing on their relative stability and structural polymorphism. Analogies in the polymorphism in these oxide/imide systems are also elucidated using on ab initio DFT thermochemistry. In the case of silicon diimide, Si(NH)2, several potential synthesis routes involving ammonia and/or ether-like NH(SiH3)2 molecular sources are proposed.Despite the structural analogy of beryllium fluoride with silica, its detailed phase diagram has yet to be established experimentally. In this case, both the static and thermally corrected phase ordering of BeF2 polymorphs using ab initio phonon-based thermochemistry are investigated. The compression behavior and mechanical instabilities of a dozen BeF2 crystalline polymorphs is also compared studied, leading to the development of a methodology to construct a BeF2 (P-T) phase diagram.
Date Created
2021
Contributors
- Masoumi, Narges (Author)
- Chizmeshya, Andrew A.V.G.C (Thesis advisor)
- Wolf, George G.H.W (Thesis advisor)
- Seo, Don D.S (Committee member)
- Trovitch, Ryan R.T (Committee member)
- Steimle, Timothy T.S (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
137 pages
Language
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.2.N.161607
Level of coding
minimal
Cataloging Standards
Note
Partial requirement for: Ph.D., Arizona State University, 2021
Field of study: Chemistry
System Created
- 2021-11-16 02:32:34
System Modified
- 2021-11-30 12:51:28
- 2 years 5 months ago
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