The local structural changes in La and Gd in doped ceria were investigated using the XAFS technique. In addition, Ce_1-xLn_xO_2-δ (Ln = La, Gd; LDC) (0 ≤ x ≤ 0.5) was synthesized through a coprecipitation method and the local structures were analyzed based on the XAFS spectra for the first and second neighbor shells of the constituent cations. For these two types of materials, the variation in the coordination number of the Ln and Ce cations showed different trends as a function of the dopant concentration, x. For LDC, a local structural ordering was formed at x ≥ 0.3 similar to a pyrochlore-type structure, in which the oxygen vacancies are preferentially located adjacent to La³⁺. For Ce_1-xGd_xO_2-δ (GDC), no distinct differences in the coordination number of the cations were observed.

The combined XAFS and XRD results successfully showed that the weighted average distances of the longer Ln-Ln (Ln = La for LDC and Ln = Gd for GDC) and shorter Ce-Ce at each composition, as obtained through XAFS analysis, fit extremely well with the lattice parameter obtained using XRD. A model of the local structural change was derived to explain the variation in the electrical conductivity during the early stage of Ln doping.

使用XAFS技术研究了掺杂二氧化铈中La和Gd的局部结构变化。此外，通过共沉淀法合成了Ce _1-x Ln _x O2 _-δ（Ln = La，Gd; LDC）（0≤x≤0.5），并根据XAFS光谱分析了第一和第二相的局部结构。组成阳离子的第二个相邻壳。对于这两种材料，Ln和Ce阳离子配位数的变化显示出不同的趋势，这是掺杂剂浓度x的函数。对于LDC，类似于烧绿石型结构，在x≥0.3处形成局部结构有序，其中氧空位优先位于La ^3+附近。对于Ce _1-x Gd _xO2 _-δ（GDC），没有观察到阳离子配位数的明显差异。

XAFS和XRD的组合结果成功地表明，通过XAFS分析获得的每个成分的更长Ln-Ln（Ln = LDC的Ln和Ln = Gd GDC的）的加权平均距离非常适合使用XRD获得的点阵参数。推导了局部结构变化的模型，以解释Ln掺杂早期阶段电导率的变化。