Synthesis of nanosized zirconium carbide by a sol-gel route

摘要

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 deg C under flowing argon, gels transformed into intimately mixed amorphous carbon and nanosized tetragonal ZrO_2- Further heat treatments above 1200 deg 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 deg C, which unfortunately also induced a mean crystallites size increase from 90 to 150 nm. Short heat treatments above 1600 deg 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.