Although several gas phase synthesis methods for nanoparticles have been developed, only few are adapted for mass-production of varoius types of nanoparticles. In this study, we developed a new method to synthesize oxide nanoparticles by gas phase reaction assisted with DC plasma. We chose ZrO2 and CeO2 as a model powder. TEM observation and specific surface area measurement showed that as-synthesized nanoparticles were in the size range of 5-100nm and they were not hollow but solid particles. From XRD results, as-synthesized nanoparticles had a high crystallinity without sintering. The present experiments suggested that the particle size is controlled by the oxygen gas feed rate of a carrier gas through a two fluid nozzle, i. e., an increase in oxygen feed rate leads to smaller nanopraticles at a constant precursor feed rate.
