Structural evolutions and oxidation behavior of Fe-doped silicon oxycarbide nanocomposites at medium temperatures

A novel Fe ion doped silicon oxycarbide (SiFeOC) ceramic was prepared by solvothermal method using methyltrim ethoxysilane, dimethyl dimethoxy silicane, and ferric nitrate as raw materials. Compared with pure SiOC ceramic, the incorporation of Fe ion into SiOC ceramic significantly enhanced phase separation of the SiOC network. Transmission electron microscopy and X-ray diffraction analysis showed that the SiFeOC ceramics were made up of amorphous SiOC, SiC and Fe3Si phases after pyrolysis at 1573 K. The anti-oxidation capabilities of such nanocomposites were also investigated at medium temperatures. Results showed that SiFeOC ceramics had better oxidation resistance properties than pure SiOC ceramics, and the phase compositions of those samples were also analyzed after the oxidation test process. This work provides a guidance to fabricate metal-modified SiOC ceramics with desired structures.