Affiliation:
1. Department of Chemistry University of Connecticut Storrs Connecticut USA
2. Institute of Materials Science University of Connecticut Storrs Connecticut USA
3. Department of Materials Science and Engineering University of Connecticut Storrs Connecticut USA
4. UConn‐ThermoFisher Scientific Center for Advanced Microscopy and Materials Analysis (CAMMA) University of Connecticut Storrs Connecticut USA
5. Department of Materials Science and Engineering and Department of Chemistry Institute of Materials Science University of Connecticut Storrs Connecticut USA
Abstract
AbstractPolysilazane (PSZ) polymers offer the ability to form silicon carbide (SiC) or silicon nitride (Si3N4) via thermal pyrolysis. The majority of studies surrounding this polymer have focused on the decomposition of PSZ to amorphous glass. Investigations into the structural defects and bonding environments of the final ceramic systems are not as frequently discussed. Examining structural defects/abnormalities can help better use PSZ‐derived ceramics in electronic and high‐temperature applications, where phase identity and microstructure are important.In this work, three PSZ‐derived polymers were synthesized with different C/N ratios (1.33, 1.0, and 1.2) via the ammonolysis condensation reaction with chlorinated silanes. The samples were named PSZ‐SiCF1‐3. Samples were then pyrolyzed under Ar in a tube furnace at 1600°C for 5 h. Characterization included X‐ray diffraction (XRD), Raman spectroscopy, X‐ray photoelectron spectroscopy, scanning transmission electron microscopy, and electron energy loss spectroscopy.XRD measurements uncovered arbitrary stacking fault (SF) measurements of 3C‐SiC to be 4.12, 1.08, and 2.12 (unitless) for samples PSZ‐SiCF1‐3. Results were supported through Raman spectroscopy and TEM. High carbon content, not higher residual nitrogen content, was more impactful for SF formation. This highlights the importance of SFs in the microstructural evolution of non‐oxide ceramics.
Funder
University of Connecticut
Subject
Materials Chemistry,Ceramics and Composites