Si–C–N–Fe nanostuctured ceramics from inorganic polymer precursors obtained by plasma polymerization

Abstract

Multicomponent powders based on SiCN and SiCN containing iron systems are of great interest as starting materials for sintering advanced ceramics and composites with improved properties for high temperature applications.We report a versatile method by which are designed inorganic polymers with a defined composition as precursors for a ceramic with induced properties. The synthesis of Si–C–N and Si–C–N–iron polymer precursors are performed in improved configuration of plasma assisted chemical vapor deposition (CVD) coupled with chemical transport reaction (CTR) with inorganic monomers, hexamethyldisilazane and ferrocene/hexamethyldisilazane as precursors. Further, the resulted polymers are then pyrolysed at 1200 °C under nitrogen atmosphere into nanostructured ceramics (such as Si3N4, Fe3C).The conversion process of the polymer precursors into a nanostructured ceramic was followed mainly by FTIR, XRD, TEM and SEM investigation. Infrared spectroscopy of polymers revealed the presence of Si–C, Si–N, C–N and hydrogenated bonds. Transmission electron microscopy showed that the polymers are made of nanometric round-shape particles with the average particle size around 20–40 nm for SiCN and 40–80 nm for SiCN containing iron.