六方相LaF3纳米晶体的水热合成法制备及结构表征

Structure characterization and hydrothermal synthesis of rhombohedral LaF3 nanocrystals

系统分析了水热合成反应过程中晶体颗粒形成的三种机制,并以La(NO3)3·6H2O化合物和NaF水溶液为前驱物,通过水热合成反应制备了白色粉末状的LaF3晶体样品,采用X射线衍射仪和透射电子显微镜分别表征了LaF3晶体样品的晶体结构、颗粒形貌和晶粒尺寸.表征结果显示,水热合成法制备的LaF3白色粉末晶体形貌规则、分散良好,具有六方相晶体结构,声子能量约365cm^-1,晶体颗粒尺寸在35nm左右.这说明水热合成法所制备的样品具有晶体颗粒度细、分散性好和纯度高制等优点.

Three mechanisms of crystal particle formation in the process of hydrothermal synthesis were systematically analyzed.The white LaF 3 crystal powder samples were prepared by hydrothermal synthesis method using La(NO 3) 3·6H 2O compound and NaF aqueous solution as precursors.The crystal structure,particle morphology and grain size of LaF 3 crystal samples were characterized by X-ray diffraction and transmission electron microscopy,respectively.The characterization results show that the morphology of the white LaF 3 powders prepared by hydrothermal synthesis method are regular and well dispersed.The crystals have hexagonal crystal structure and the crystal particle size is about 35 nm.The LaF 3 phonon energy is about 365 cm -1 .These results illustrate that the samples prepared by hydrothermal synthesis have the advantages of fine crystal particle size,good dispersion and high purity.