| abstract |
Process for synthesizing a powder, comprising the following successive steps: (A) preparation of a mother liquor comprising: i. an oxide base constituent or a precursor of the said base constituent and an additional constituent of formula MC, the said additional constituent being composed of: an agent M chosen from the group of oxo anions, anions of elements from column 17 of the Periodic Table of the Elements, hydroxide OH-, and mixtures thereof, and a complement C, this complement being inorganic when the agent is hydroxide OH-; or ii. an oxide base constituent or a precursor of the said base constituent incorporating an agent M chosen from the group of oxo anions, anions of elements from column 17 of the Periodic Table of the Elements, and mixtures thereof; (B) preparation, hydrothermally from the said mother liquor, of a sol whose crude particles have a maximum size of greater than 10 nm and less than 250 nm and even of less than 100 nm; (C) washing of the sol so as to obtain, after an optional drying step, a powder comprising more than 99.3% of the said base constituent, as mass percentage on the basis of dry matter. |