en Research Paper Research Paper Well crystallized pure calcium zirconate (CaZrO3 ) nanopowder was successfully synthesized using the molten-salt method. CaCl2 , Na 2CO3, micro-ZrO 2and nano-ZrO 2 were used as starting materials. On heating, Na2CO3 reacted with CaCl 2to form NaCl and CaCO 3. Nano CaZrO 3 was formed by reacting equimolar amounts of in situformed CaCO 3 (or CaO) and ZrO 2 in molten Na 2CO3-NaCl eutectic mixture. CaZrO 3 particle size and synthesis temparture was tailored as a function of ZrO 2particle size. Due to the usage of nano-ZrO 2 , the molten salt synthesis (MSS) temperature was decreased and possible impurity phases in the final product were suppressed. The synthesis temperature was lowered to 800°C and soaking time of the optimal synthesis condition was reduced to 3h. After washing with hot-distilled water, the n-ZrO2sample heated at 800°C for 3h, was single phase CaZrO 3with 70-90 nm in particle size, while the m-ZrO 2sample heated at 1000°C for 3h, was single phase CaZrO 3 with 250-400 nm in particle size. Based on the TEM observation and thermodynamic analysis, the synthesized CaZrO 3 grains retained the morphology of the ZrO2 nanopowders, which indicated that a template formation mechanism play a dominant role in synthesis process Molten salt method, Nano materials, Calcium zirconate, Template growth 32 38 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-3-189&slc_lang=en&sid=1 R. Fazli 180031947532846002676 180031947532846002676 No Centre of Excellence for Advanced Materials and processing, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. F. Golestani-Fard 180031947532846002677 180031947532846002677 No Centre of Excellence for Advanced Materials and processing, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. Y. Safaei-Naeini Yousef.Safaei@gmail.com 180031947532846002678 180031947532846002678 Yes Centre of Excellence for Advanced Materials and processing, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. S. Zhang 180031947532846002679 180031947532846002679 No Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK.