| Abstract Scope |
In this study, an allylhydropolycarbosilane polymer precursor was used to synthesize SiC at 1200°C, 2200°C, and 2500°C in an argon atmosphere. Detailed structural evolutions were investigated by experimental and analytical methods. The material is comprised of a Si-containing amorphous matrix phase and a free-carbon phase till 1200 oC. The amorphous matrix phase is comprised of SixCy [x+y=4; 0≤{x,y}≤4] and free carbon. With increasing pyrolysis temperature, the amorphous matrix becomes more ordered, accompanied by a transition among SixCy followed by formation of stoichiometric SiC and nanocrystalline graphite. At ultrahigh temperatures (>2200 oC), SiC undergoes a complete phase transformation from the amorphous to the crystalline phase. The current research on the phase and nanostructure of polymer derived SiC at ultrahigh temperatures can lead to a better understanding of its properties and potential applications. |