Nanodomain Structure of Carbon-Rich Silicon Carbonitride Polymer-Derived Ceramics

摘要

The presence of nanodomains in polymer-derived ceramics constitutes one of the most intriguing features of this class of materials. In the present work, the nanostructure of novel carbon-rich silicon carbonitride (SiCN) ceramics synthesized via thermolysis of poly(methylphenylsilylcarbodiimide), -[Ph(CH_3) Si-NCN]_n-, at 1300°, 1500°, 1700°, and 2000C is investigated by micro-Raman spectroscopy, X-ray powder diffractometry, and small-angle X-ray scattering (SAXS). The structural information obtained from these experimental methods is combined together with theoretical modeling of the SAXS data to obtain a detailed model of the temperature-dependent evolution of nanodomains comprised of free carbon, SiC, and Si_3N_4 in SiCN-based ceramics.