Six variants of direct and reverse coprecipitation of a mixture of salts by an aqueous solution of ammonia or an ammonia buffer solution with pH 9.5 are considered to optimize the technological scheme for the synthesis of zirconium dioxide nanopowders stabilized with 2.5 mol.% yttrium oxide. The influence of the storage time of the mixture of salt solutions before precipitation on the phase and chemical composition, apparent density, and open porosity of sintered specimens was investigated. The best results were obtained using reverse precipitation with an ammonia buffer as precipitant.

中文翻译：

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生产二氧化锆纳米粉的溶胶-凝胶条件的优化

可以考虑通过氨水溶液或pH值为9.5的氨缓冲溶液对盐混合物进行直接和反向共沉淀的六个变体，以优化合成用2.5摩尔％氧化钇稳定的二氧化锆纳米粉的工艺方案。研究了沉淀前盐溶液混合物的储存时间对烧结试样的相和化学组成，表观密度和开孔率的影响。使用氨水缓冲液作为沉淀剂进行反向沉淀可获得最佳结果。