Low temperature synthesis of ZrB ₂ powder synergistically by borothermal and carbothermal reduction

To achieve a ZrO ₂-B-C ternary solid-state reaction, a small amount of carbon was introduced into a binary system of ZrO ₂ and boron. Amorphous hydrous ZrO ₂ precursor was firstly prepared through precipitation method using zirconyl nitrate and ammonia at room temperature. Then, ZrB ₂ powder was successfully synthesized using the as-prepared amorphous hydrous nano-ZrO ₂ via borothermal and carbothermal reduction (BCTR) by amorphous boron and nanocarbon powders under flowing argon. Plate-like ZrB ₂ particles with a uniform distribution and ca. 1.0 μm in two-dimensions were obtained with a B/Zr molar ratio of 4, and 5 wt.% (total weight of dry hydrous ZrO ₂ and boron) nanocarbon at 1550 °C for 2 h.