Understanding the local structure of Eu3+- and Y3+-stabilized zirconia: insights from luminescence and X-ray absorption spectroscopic investigations
Understanding the local structure of Eu3+- and Y3+-stabilized zirconia: insights from luminescence and X-ray absorption spectroscopic investigations
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DOI：
10.1007/s10853-020-04768-3
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发表时间：
2020-05-18
影响因子：
4.5
通讯作者：
Huittinen, N.
中科院分区：
文献类型：
--
作者：
Eibl, M.;Shaw, S.;Huittinen, N.
本研究结合了Eu3+或Y3+/Eu3+共掺的四方和立方氧化锆的体相结构和光谱研究，以深入了解固溶体的形成过程。我们的块体结构表征表明，随着掺杂量的增加(从8%增加到26%)，掺杂均匀地分布在ZrO2主体结构中，导致了块体对称性的增加。然而，用发光光谱(TRLFS)测定的Eu3+掺杂剂周围的局域位置对称性在所有样品中仍然很低。X射线对分布函数和X射线吸收光谱的结果表明，稳定的氧化锆结构的平均配位环境基本保持不变。尽管存在非常恒定的平均掺杂环境，但位选择性TRLFS数据显示，在ZrO2固体结构中存在三个不等价的Eu3+环境。这些Eu3+环境被认为是由于Eu3+在表面位置的掺入，随着晶体尺寸的减小，Eu3+的丰度增加，以及在氧空位相对于掺杂阳离子的位置不同的两个主体位置上的掺入。
This study combines bulk structural and spectroscopic investigations of Eu3+- or Y3+/Eu3+ co-doped tetragonal and cubic zirconia polymorphs to gain an in-depth understanding of the solid solution formation process. Our bulk structural characterizations show that the dopant is homogenously distributed in the ZrO2 host structure resulting in an increase of the bulk symmetry with increasing dopant substitution (from 8 to 26 mol%). The local site symmetry around the Eu3+ dopant, however, determined with luminescence spectroscopy (TRLFS), remains low in all samples. Results obtained with X-ray pair distribution function and X-ray absorption spectroscopy show that the average coordination environment in the stabilized zirconia structures remains practically unchanged. Despite this very constant average dopant environment, site-selective TRLFS data show the presence of three nonequivalent Eu3+ environments in the ZrO2 solid structures. These Eu3+ environments are assumed to arise from Eu3+ incorporation at superficial sites, which increase in abundance as the size of the crystallites decrease, and incorporation on two bulk sites differing in the location of the oxygen vacancies with respect to the dopant cation.