The effects of processing parameters on molten salt synthesis of CaZrO3 nano-powders using oxide precursors

Nano-powders of CaZrO3 were successfully synthesized at 650 °C using the molten-salt method, and the effects of processing parameters, such as temperature, holding time and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, LiCl, CaCO3 and nano-ZrO2 were used as starting materials. On heating, CaCl2–LiCl molten eutectic salt provided a liquid medium for reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 550 °C and that, after the temperature was increased to 1000 °C, the amounts of CaZrO3 in the resultant powders increased with a concomitant decrease in CaCO3 and ZrO2 contents. After washing with hot-distilled water, the samples heated for 3 h at 650 °C were single-phase CaZrO3 with 90–95 nm particle size. Furthermore, the synthesized CaZrO3 particles retained the size and morphology of the ZrO2 powders, which indicated that a template formation mechanism dominated the formation of CaZrO3 by molten-salt method.