Solvent and plasma gas influence on the synthesis of Y2O3 nanoparticles by suspension plasma spraying

Suspension plasma spraying was used to synthesize Y2O3 nanoparticles. The Y2O3 starting material was first dispersed in a solvent to form a suspension and then injected axially into the plume of an inductive radio frequency plasma. It was found that the as-sprayed Y2O3 particles had a size distribution from nano to micron scale and various morphological features, which varied with processing conditions as well as solvent and plasma gas type. In comparison with water, organic solvents led to a higher productivity and smaller particle size, whereas water introduced impurities such as Y2O2C2, which is isotypic to La2O2C2. Introduction of oxygen as an auxiliary plasma gas was an effective way to eliminate this impurity. In addition, complete combustion of the organic solvent and recombination of oxygen atoms above 4000 K also elevated the heat treatment degree of Y2O3. As a result, application of O2 with an organic solvent resulted in an even smaller mean particle size and narrower size distribution.