摘要
以Er_(2)O_(3)和正硅酸乙酯(TEOS)为原料,采用并流共沉淀法合成了纳米Er_(2)SiO_(5)粉体。研究了前驱体Si/Er摩尔比、煅烧温度以及反应体系pH值对Er_(2)SiO_(5)物相组成和显微结构的影响,并探讨了Er_(2)SiO_(5)粉体的合成机理。结果表明:前驱体Er/Si摩尔比为20∶12,煅烧温度为1300℃时,Er_(2)SiO_(5)粉体由X2-Er_(2)SiO_(5)纯相组成,具有近球形形貌特征。低Er/Si摩尔比可降低Er_(2)SiO_(5)的结晶温度并促进X2-Er_(2)SiO_(5)的生成,反应体系pH值的升高则对[Si—O—Er]结构的生成具有一定的促进作用。Er_(2)SiO_(5)前驱体是以[Si—O—Er]网络结构形式存在的,煅烧过程中通过分解和结构重组逐步生成Er_(2)SiO_(5),Er_(2)O_(3)杂质相的生成是高Er/Si摩尔比前驱体[Si—O—Er]网络结构中的Er^(3+)在Er_(2)SiO_(5)结晶过程中的析出造成的。
The nano-sized Er_(2)SiO_(5)powders were prepared by cocurrent coprecipitation method using Er_(2)O_(3)and tetraethyl orthosilicate(TEOS)as raw materials.The effects of precursor Si/Er molar ratio,calcination temperature,and pH value of reaction system on Er_(2)SiO_(5)phase composition and microstructure were investigated,and the synthesis mechanism of Er_(2)SiO_(5)powders was discussed.Results show that pure Er_(2)SiO_(5)powders with nearly spherical morphology can be obtained from the precursor with Er/Si molar ratio of 20∶12 after being calcined at temperatures at 1300℃.Low Er/Si molar ratio can reduce the crystallization temperature of Er_(2)SiO_(5)and promote the formation of X2-Er_(2)SiO_(5).The increase of pH value in the reaction system has a certain promotion effect on the formation of[Si—O—Er]structure.During the synthesis process,a[Si—O—Er]network structure is formed in the Er_(2)SiO_(5)precursor.The[Si—O—Er]network will transform to Er_(2)SiO_(5)through decomposition and structural reorganization during the calcination process.The Er_(2)O_(3)impurity is caused by the precipitation of Er^(3+)of the[Si—O—Er]network structure in the precursor with high Er/Si molar ratio during the crystallization process of Er_(2)SiO_(5).
作者
佟永乐
王雅雷
刘蓉
刘怀菲
武囡囡
程慧聪
TONG Yongle;WANG Yalei;LIU Rong;LIU Huaifei;WU Nannan;CHENG Huicong(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2024年第3期52-60,共9页
Journal of Materials Engineering
基金
国家科技重大专项(2017-Ⅵ-0020-0092)
湖南省教育厅科学研究项目(19C1913)。
