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ELECTRONIC PROPERTIES AND MICROSTRUCTURES OF AMORPHOUS SICN CERAMICS DERIVED FROM POLYMER PRECURSORS
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| Title | ELECTRONIC PROPERTIES AND MICROSTRUCTURES OF AMORPHOUS SICN CERAMICS DERIVED FROM POLYMER PRECURSORS |
| Author | JIANG, TAO
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| Keywords | Polymer derived ceramics
SiCN
Electronic properties
Microstructures
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| Abstract | Polymer-derived ceramics (PDCs) are a new class of high-temperature materials synthesized by thermal decomposition of polymeric precursors. These materials possess many unique features as compared with conventional ceramics synthesized by powder metallurgy based processing. For example, PDCs are neither amorphous nor crystalline. Instead, they possess nano-domain structures. Due to the direct chemical-to-ceramic processing, PDCs can be used for making components and devices with complex shapes. Thus, understanding the properties and structures of these materials are of both fundamental and practical interest. In this work, the structures and electronic behavior of polymer-derived amorphous silicon carbonitrides (SiCNs) were investigated. The materials were synthesized by pyrolysis of a commercially available liquid precursor. Ceramic materials with varied structures/properties were successfully synthesized by modifying the precursor and using different pyrolysis temperatures. The structures of the obtained materials were studied using XRD, solid state NMR, EPR, FTIR and Raman Spectroscope. The electronic behavior of the materials was investigated by measuring I-V curves, Hall effects, temperature dependent conductivity. The experiments were also performed to measure UV-Visible absorption and dielectric properties of the materials. This work leads to the following significant progresses: (i) developed quantitative technique for measuring free carbon concentration; (ii) achieved better understanding of the electronic conduction mechanisms and measured electronic structures of the materials for the first time; and (iii) demonstrated that these materials possess unusual dielectric behavior and provide qualitative explanations. |
| Adviser | An, Linan
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| Publisher | University of Central Florida |
| Degree | Ph.D.
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| Degree Discipline | Department of Mechanical, Materials and Aerospace Engineering
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| Degree Grantor | Engineering and Computer Science
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| Degree Program | Materials Science & Engr PhD
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| Graduation Date | 2009-01-01 |
| Type | Doctoral dissertation
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| Access Level | Public - Allow Worldwide Access
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| Release Date | 2009-09-18 |
| Repository | University Archives
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| Repository Collection | Electronic Theses and Dissertations
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| Identifier | CFE0002702 |
| Access Link | http://purl.fcla.edu/fcla/etd/CFE0002702 |
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