Improved crystallisation of polysilazane‐derived Si 3 N 4 /SiC nanocomposites with Fe 2 O 3 catalyst

Abstract In the present study, the use of a 3 wt% Fe 2 O 3 catalyst improved the crystallisation of polysilazane PSN2. Crystallisation peaks of higher intensity were observed for Si 3 N 4 and SiC at 1250 °C by using a 3 wt% Fe 2 O 3 catalyst than at 1500 °C without Fe 2 O 3 . Besides, the effects of temperature on the morphology of the samples were determined through scanning electron microscopy. Porous structures were observed at 1250 °C and these structures were transformed to flaky and near‐spherical nanoparticles as the temperatures were increased to 1350 and 1450 °C, respectively. Finally, the mechanism of Fe origination from Fe 2 O 3 reduction, the production of a supersaturated liquid alloy, and the release and diffusion of N 2 were proposed for Si 3 N 4 formation.