Synthesis of nanosized zirconium carbide by a sol–gel route

Nanosized zirconium carbide was synthesized by a new simple sol–gel method using zirconium n-propoxide, acetic acid as chemical modifier, and saccharose as carbon source. When heat-treated at 900 °C under flowing argon, gels transformed into intimately mixed amorphous carbon and nanosized tetragonal ZrO2. Further heat treatments above 1200 °C led to the formation of zirconium carbide with some dissolved oxygen in the lattice. Oxygen content could be reduced by increasing the heat treatment temperature from 1400 to 1600 °C, which unfortunately also induced a mean crystallites size increase from 90 to 150 nm. Short heat treatments above 1600 °C were carried out to further purify the samples and to limit the particles growth. A compromise between purity and average crystallite's size could then be found. Powders were assessed using X-ray diffraction, thermal analysis and scanning electron microscopy.