Effect of Thermal Initiator Concentrations on the Structure and Optical Band Gaps of Polyvinylsilazane-Derived SiOCN Ceramics.

Si OCN ceramics are formed by the thermal decomposition of a polyvinylsilazane precursor in the presence of a dicumyl peroxide ( DP) thermal initiator with different concentrations. The Si OCN ceramics pyrolyzed at 1000°C with different concentrations of DP are characterized with X-ray diffraction, transmission electron microscope, electron paramagnetic resonance, and UV-visible spectroscopy. We find that the structure and optical band gap of the Si OCN ceramics can be changed by altering the concentration of DP. There is a critical concentration, at which the structural and optical behavior varied in different ways as a function of the concentration of DP. The detailed mechanism is discussed. [ABSTRACT FROM AUTHOR]