【摘要】 采用硬脂酸凝胶法制备了CeO2 纳米晶。XRD分析表明 ,当焙烧温度为 4 50～ 90 0℃时 ,所合成的CeO2 纳米晶均属于单相立方晶系 ,空间群为O5H -FM3M ;计算表明 ,随焙烧温度的升高 ,平均晶粒度增大 ,而平均晶格畸变率则随平均晶粒度的增大而减小 ,表明粒子越小 ,晶格畸变越大 ,晶粒发育越不完整。TEM分析表明 ,CeO2 纳米晶呈球形 ,粒度随焙烧温度的增加而增大。热失重分析表明 ,当焙烧温度高于 750℃时 ,CeO2 中的杂质基本挥发完毕。相对密度分析表明 ,随CeO2 纳米晶粒度的增大 ,粉末的密度增加。更多还原

【Abstract】 CeO\-2 nanocrystalline particulates of different sizes were prepared by stearic acid gel method.XRD patterns showed that the synthesized CeO\-2 was cubic in structure with single\|phase when calcination temperature was 450-900℃,space group was O\+5\-H-F M3M .Calcination revealed that the mean crystalline size increased with the increase of calcinstion temperature,but average crystal lattice distortion rate decreased with the increasing in the average crystalline size.This indicated that the smaller the particle size,the bigger crystal lattice distortion,the worse the crystal growed.TEM photos revealed that CeO\-2 particles were spherical in shape,and the mean sizes of the C eO\-2 particles increased with the increase of calcination temperatures.Weight loss analysis indicated that the impurity in CeO\-2 completely volatilized when calcination temperature was above 750℃.The density of nanocrystalline CeO\-2 powders analysis showed that the density of CeO\-2 nanocrystalline powders increased with the increasing in CeO\-2 particles sizes.更多还原