Differential interplay between Ce and U on local structures of U1-xCexO2 solid solutions probed by X-ray absorption spectroscopy
Differential interplay between Ce and U on local structures of U1-xCexO2 solid solutions probed by X-ray absorption spectroscopy
复制标题
X射线吸收光谱探测Ce和U对U1-xCexO2固溶体局部结构的微分相互作用
DOI：
10.1016/j.jnucmat.2018.12.042
复制
发表时间：
2019
影响因子：
3.1
通讯作者：
Wang Jian Qiang
中科院分区：
文献类型：
--
作者：
Cao Hanjie;Bao Hongliang;Lin Xiao;Lin Jian;Zhang Linjuan;Huang Yuying;Wang Jian Qiang
采用共沉淀法合成了铀-铈混合氧化物U1-xCexO2(x = 0.05，0.20，0.35，0.50，0.65，0.80)。用X射线衍射法结合X射线吸收光谱证实了U1-xCexO2为固溶体，晶胞参数符合Vegard定律。用扩展X射线吸收精细结构(EXAFS)分别研究了Ce含量对U1-xCexO2固溶体中U和Ce局域结构的影响。值得注意的是，U_(1-x)CexO_2中U和Ce附近的局域无序度并不相等。U和Ce在U1-xCexO2的局域结构上存在着不同的相互作用。当Ce含量保持在35%左右或更高时，U的局部结构有序度随着Ce含量的增加而增加。相反，一旦在CeO2中加入铀，Ce局域结构的无序度就会随着U含量的增加而增加。
Uranium–cerium mixed oxides U1-xCexO2(x = 0.05, 0.20, 0.35, 0.50, 0.65, 0.80) were synthesized by co-precipitation method. The U1-xCexO2samples were confirmed to be solid solutions with lattice parameters following Vegard's law by using X-ray diffraction technique combined with X-ray absorption spectroscopy. The effects of cerium content on the local structures of U and Ce in the U1-xCexO2solid solutions were further studied by extended X-ray absorption fine structure (EXAFS) at the UL3edge and CeKedge, respectively. Significantly, the local disorder degree around U and Ce in the U1-xCexO2were found to be not equivalent. There is differential interplay between U and Ce on the local structures of the U1-xCexO2. The order degree in the local structure of U increases with the content of cerium when the Ce content is kept about 35% or more. In contrast, the disorder degree in the local structure of Ce increases with U content once uranium is added into CeO2.