| 摘要 |
PROBLEM TO BE SOLVED: To provide plate-like crystals having a relatively large particle size and having little contamination of crystals of a relatively small particle size.SOLUTION: Hydrothermal synthesis is carried out by adding oxide powder having an orthorhombic crystal structure and surface active agent to alkali hydroxide solution to synthesize seed crystals, hydrothermal synthesis is carried again by adding seed crystals, oxide powder having an orthorhombic crystal structure, and surface active agent to the seed crystals and the alkali hydroxide solution, the plate-like crystals obtained after the reaction of the second hydrothermal synthesis is washed with an organic solvent, the reaction product of the plate-like crystals after the washing is sintered at 170°C or higher and 700°C or lower. |
