REACTIVE CERIUM(IV) OXIDE POWDERS BY THE HOMOGENEOUS PRECIPITATION METHOD
REACTIVE CERIUM(IV) OXIDE POWDERS BY THE HOMOGENEOUS PRECIPITATION METHOD
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DOI：
10.1111/j.1151-2916.1993.tb03942.x
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发表时间：
1993-06-01
影响因子：
3.9
通讯作者：
CHEN, IW
中科院分区：
文献类型：
--
作者：
CHEN, PL;CHEN, IW
在六亚甲基四胺存在下，通过陈化硝酸铈(III)溶液制备了CeO2粉末。Ce3+在沉淀物中发生氧化，湿沉淀物在任何热处理前被鉴定为结晶的CeO2。冷压粉末可以在低至1250摄氏度的温度下在短短6分钟内烧结到全密度。此外，粉末的烧结性对焙烧温度、颗粒大小或生坯密度不敏感。在850℃下焙烧的微晶尺寸为600埃的粉末具有与450℃下焙烧的微晶尺寸为145埃的粉末一样好的烧结性。讨论了CeO2直接析出的机理及其与良好的烧结性的关系。
CeO2 powders have been prepared by aging a cerium(III) nitrate solution in the presence of hexamethylenetetramine. Oxidation of Ce3+ occurs in the precipitate and the wet precipitate is identified as crystallized CeO2 before any heat treatment. The cold-pressed powders can be sintered to full density at temperatures as low as 1250-degrees-C in just 6 min. Moreover, the sinterability of the powders is insensitive to the calcination temperatures, particle size, or green density. The powders calcined at 850-degrees-C with a crystallite size of 600 angstrom have a sinterability as good as the powders calcined at 450-degrees-C with a crystallite size of 145 angstrom. The mechanisms for direct CeO2 precipitation and its relation to the excellent sinterability are discussed.