|About this Abstract
||MS&T22: Materials Science & Technology
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||Using a Reactive Hydrogen Atmosphere to attain Polymer-Derived SiCN ceramics
||Akshada Hande, Peter Kroll
|On-Site Speaker (Planned)
We compare the impact of hydrogen and nitrogen atmosphere during the processing of Durazane 1800(PSZ20). Visual differences appear in bulk and powdered samples. FTIR spectroscopy performed on H2-pyrolyzed samples indicates the persistence of carbidic carbon integrated into the SiCN host structure. Complementary Raman analysis supports the presence of graphitic segregations in N2-pyrolyzed samples but does not indicate similar constituents in H2-pyrolyzed samples. Subsequent additional annealing at 1300 °C and 1500 °C under Ar converts the amorphous SiCN into poly-crystalline ceramics. Phase analysis by XRD shows that N2-pyrolyzed samples further annealed under Ar, completes the carbothermal reduction and yields silicon carbide(SiC). In contrast, H2-pyrolyzed sample further annealed in Ar results in a SiC and silicon nitride (Si3N4), with a carbothermal reduction being significantly delayed even at 1500°C. We show that the amount of excess carbon present in the chosen SiCN-polymer can be tailored using hydrogen atmosphere during pyrolysis.