【摘要】 用改进的柠檬酸溶胶-凝胶法制备了纳米PrOy-ZrO2固溶体.采用XRD,Ram an和TEM等技术对纳米PrOy-ZrO2进行了表征.结果表明,改进的柠檬酸溶胶-凝胶法制备的PrOy-ZrO2固溶体于650℃焙烧后晶粒大小在5~10 nm之间;于950℃焙烧(Pr>16%)后晶粒大小在20 nm左右.Pr能有效地使ZrO2稳定在四方或立方晶相.随Pr含量的增加,PrOy-ZrO2固溶体的物相结构从单斜相逐步向四方和立方相转变.XRD和Ram an得到的物相结构的差别表明,PrOy-ZrO2固溶体表层和体相结构存在不一致性,随Pr含量增加,体相逐步按照m→t→c的物相转变,表层按照m→t→t″的物相转变.表层更易生成低对称性和无序结构.更多还原

【Abstract】 The characterization for PrOy-ZrO2 solid solutions prepared by improved sol-gel method was performed by means of Raman,XRD,TEM and so on.It is found that the grain size of PrOy-ZrO2 solid solution calcined at 650 ℃ is 5～10 nm,and that of PrOy-ZrO2 solid solution calcined at 950 ℃[x(Pr)>16%] is about 20 nm.At a higher Pr content,phase transformation towords a higher-symmetrical phase(tetragonal or cubic) was observed.The results of phase analysis obtained by Raman spectroscopy were different from the corresponding results of XRD,which implies a structure difference between the surface and the bulk shell of the samples.With the increase of the Pr content,the m→t→c phase tramsformation occurred in the bulk area and the m→t→t″ phase tramsformation occurred in the surface area.The surface region is more easily to form a low symmetry and disorder structure.更多还原