| 摘要 |
<p>Powder comprising more than 50% by volume of a crystalline phase containing cerium oxide, as a percentage of the total volume of the phases of the powder, and a chemical composition, as a percentage by weight on the basis of the oxides and for a total of 100%, such that: - CeO2≥50%, - SiO2≤10%, - 1%≤ZrO2 + TiO2≤30%, provided that 0.5%≤TiO2≤20%, Sc2O3 + Y2O3 + oxides of lanthanide(s) except CeO2≤40%, - A12O3≤10%, - Na2O + K2O≤5%, - B2O3≤0.1%, - P2O5≤0.1%, other oxides≤5%, and comprising more than 90% by weight of crystallites, which are isolated or in agglomerated form, all of said crystallites having - a median circularity squared C2 50 > 0.95, and ~ a mean dimension dm of between 10 nm and 1000 nm.</p> |
