Gd_(2)SiO_(5)纳米粉体的并流化学共沉淀法合成  

Synthesis of Gd_(2)SiO_(5)nano-powders by cocurrent chemical co-precipitation method

作　　者：刘蓉 王雅雷[1] 武囡囡 刘怀菲 刘如铁[1] 程慧聪 LIU Rong;WANG Yalei;WU Nannan;LIU Huaifei;LIU Rutie;CHENG Huicong(Institute of Powder Metallurgy,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University of Forestry Science and Technology,Changsha 410004,China)

机构地区：[1]中南大学粉末冶金研究院,长沙410083 [2]中南林业科技大学材料科学与工程学院,长沙410004

出　　处：《航空材料学报》2021年第2期89-97,共9页Journal of Aeronautical Materials

基　　金：国家科技重大专项(2017-VI-0020-0092);中南林业大学材料表面与界面科学与技术湖南省重点实验室(KFBJM2019005)。

摘　　要：以Gd_(2)O_(3)和正硅酸乙酯(TEOS)为原材料,采用并流化学共沉淀法合成Gd_(2)SiO_(5)粉体材料。研究Gd_(2)SiO_(5)前驱体的热响应特征、Gd_(2)SiO_(5)粉体的物相组成和微观形貌,并对Gd_(2)SiO_(5)粉体的合成机理进行初步探讨。结果表明:前驱体的低Gd/Si摩尔比和反应体系的高pH值会导致Gd_(2)SiO_(5)粉体生成Gd_(9.33)(SiO_(4))_(6)O_(2)杂质相,相反则会导致生成Gd2O3杂质相。当Gd/Si摩尔比为20∶11、pH值为9~10、合成温度为1000~1300℃时,合成的粉体纯度较高,Gd_(2)SiO_(5)颗粒呈不规则形貌特征,平均粒度为100~200 nm。Gd_(2)SiO_(5)合成过程中,前驱体以一种—[Si—O—Gd]—网络结构存在,在煅烧过程中逐渐转化为Gd_(2)SiO_(5)晶体以及Gd_(9.33)(SiO_(4))_(6)O_(2)和Gd_(2)O_(3)杂相。In this paper,nano-sized Gd_(2)SiO_(5)powder was synthesized by a cocurrent chemical co-precipitation method with Gd2O3 and TEOS as raw materials.The thermal behavior of precursor,phase composition and microstructure of the obtained powder were investigated,the synthesis mechanism was also discussed.The results show that lower Gd:Si molar ratio in precursor and higher pH value in reaction system can lead to the formation of Gd_(9.33)(SiO_(4))_(6)O_(2)phase.On the contrary,Gd2O3 impurity is formed in the obtained Gd_(2)SiO_(5)powder.In this study,the relatively pure Gd_(2)SiO_(5)powder can be synthesized at 1000-1300℃with Gd/Si molar ratio as 20:11 and pH value in the range of 9-10.The obtained powder inhibits irregular morphology with average grain size of 100-200 nm.During the synthesis process,the precursor is generated in the form of—[Si—O—Gd]—network,and then translated to Gd_(2)SiO_(5)grains,as well as Gd_(9.33)(SiO_(4))_(6)O_(2)and Gd_(2)O_(3)impurities.

关 键 词：Gd_(2)SiO_(5)粉体 并流共沉淀法 Gd/Si摩尔比 反应体系pH值 合成机理 

分 类 号：TQ174.75[化学工程—陶瓷工业]