Effect of Pressure on Synthesis of Pr-Doped Zirconia Powders Produced by Microwave-Driven Hydrothermal Reaction

[摘要] A high-pressure microwave reactor was used to study the hydrothermal synthesis ofzirconia powders doped with 1 mol%Pr. The synthesis was performed in the pressure rangefrom 2 to 8 MPa corresponding to a temperature range from 215C∘to 305C∘. This technologypermits a synthesis of nanopowders in short time not limited by thermal inertia of the vessel.Microwave heating permits to avoid contact of the reactants with heating elements, and is thusparticularly well suited for synthesis of doped nanopowders in high purity conditions.A mixture ofZrO2particles with tetragonal and monoclinic crystalline phases, about 15 nm in size, was obtained.The p/T threshold of about 5-6 MPa/265–280C∘was necessary to obtain good quality ofzirconia powder. A new method for quantitative description of grain-size distribution was applied, which isbased on analysis of the fine structure of the X-ray diffraction line profiles. It permitted tofollow separately the effect of synthesis conditions on the grain-size distribution of themonoclinic and tetragonal phases.

[学科分类] 材料工程