EFFECT OF ZrO2 PARTICLE SIZE ON MORPHOLOGY and SYNTHESIS OF NANO CaZrO3 Via MOLTEN SALT METHOD

Well crystallized pure calcium zirconate (cazro3) nanopowder was successfully synthesized using themolten-salt method. cacl2, na2co3, micro-zro2 and nano-zro2 were used as starting materials. on heating, na2co3reacted with cacl2 to form nacl and caco3. nano cazro3 was formed by reacting equimolar amounts of in situformedcaco3 (or cao) and zro2 in molten na2co3-nacl eutectic mixture. cazro3 particle size and synthesistemparture was tailored as a function of zro2 particle size. due to the usage of nano-zro2, the molten salt synthesis(mss) temperature was decreased and possible impurity phases in the final product were suppressed. the synthesistemperature was lowered to 800°c and soaking time of the optimal synthesis condition was reduced to 3h. afterwashing with hot-distilled water, the n-zro2 sample heated at 800°c for 3h, was single phase cazro3 with 70-90 nmin particle size, while the m-zro2 sample heated at 1000°c for 3h, was single phase cazro3 with 250-400 nm inparticle size. based on the tem observation and thermodynamic analysis, the synthesized cazro3 grains retained themorphology of the zro2 nanopowders, which indicated that a template formation mechanism play a dominant role insynthesis process.