Crystallization behavior of polymer-derived Si–B–C–N ceramics in a high-pressure nitrogen environment

Abstract

This communication presents the effects of nitrogen pressure on the crystallization behavior of Si3.0B1.1C5.3N3.0 ceramics annealed at 1800 °C for 3 h. Transmission electron microscopy observation reveals that increasing nitrogen pressure results in the retardation of the crystallization process. Besides SiC and Si3N4 nanocrystals, individual large crystallites were also detected. These crystals were composed only of Si and N, and they possessed hexagonal structure with lattice parameters a = 0.737 nm and c = 0.536 nm. Crystallites of this novel phase were more frequently found with increased nitrogen pressure.