In this study, the pure and silicon-alloyed isotropic pyrolytic carbons have been deposited in a fluidized bed.
The characteristics of pyrolytic carbon, as measured by density, apparent crystallite size, and viewed metallographically under polarized light, can be easily controlled by adjusting the deposition parameters such as deposition temperature and propane flow rate or silicon concentration. The density of isotropic pyrolytic carbons deposited from propane between 1200℃ and 1440℃ increases with increasing propane flow rate and decreasing deposition temperature from 1.73g/㎤ to 2.08g/㎤. The apparent crystallite size, Lc parameter appears to depend only on deposition temperature, being entirely independent of the propane flow rate.
Codeposition of silicon in the presence of chlorine enchances the deposition rate of the silicon-alloyed pyrolytic carbons. The carbon matrix density of the silicon-alloyed carbons deposited from propane and methyltrichlorosilane from 2.05g/㎤ for a silicon concentration around 9wt.% to 1.67g/㎤ for a silicon concentration of 36.7wt.%. The Lc parameter of the silicon-alloyed carbons appears to depend only on deposition temperature, being entirely independent of the silicon concentration.
