Gd_2Zr_2O_7纳米晶的制备及表征

Preparation and Characterization of Gd_2Zr_2O_7 Nanocrystals

以柠檬酸(CA)为螯合剂,乙二醇(EG)为分散剂,通过Pechini法合成出Gd2Zr2O7纳米晶,讨论了pH值、分散剂含量以及热处理温度对样品物相和形貌的影响,采用SEM、TG-DTA、XRD和TEM等测试手段对样品进行了表征。结果表明:溶胶pH值=6,乙二醇含量为柠檬酸的2倍,经900℃煅烧2 h获到Gd2Zr2O7样品结晶度高、晶型完整,为缺陷型萤石结构,属于Fm3m空间群,且粒度均匀,粒径约50 nm,d111面间距为0.304 nm。

Gd2Zr2O7 nanocrystals were prepared by Pechini method using citric acid as chelating agent and ethylene glycol as dispersing agent.The effects of pH value,the content of dispersing agent,and thermal treatment temperature on structure and morphology are investigated by scanning electron microscope technique,thermal gravimetric-differential thermal analysis,X-ray diffraction technique,and transmission electron microscopy technique.The results showed that the Gd2Zr2O7 nanocrystals have higher crystallinity with an excellent defective fluorite structure(which belongs to the Fm3m space group),when calcined at 900 ℃ for 2 h,the sol pH value is controlled at 6,and the amount of ethylene glycol is twice as much as that of citric acid.In addition,the powders have a uniform granularity with a dimension of about 50 nm,and the d111 interplanar distance is 0.304 nm.