Structural characterization of the CeO2/Gd2O3 mixed system by synchrotron X-ray diffraction
Structural characterization of the CeO2/Gd2O3 mixed system by synchrotron X-ray diffraction
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DOI：
10.1016/j.jssc.2012.01.056
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发表时间：
2012-06-01
影响因子：
3.3
通讯作者：
Plaisier, Jasper
中科院分区：
文献类型：
--
作者：
Artini, Cristina;Costa, Giorgio A.;Plaisier, Jasper
CeO2/Gd2O3混合体系的结构测定是一个非常重要的问题，因为Ce4+和Gd3+的离子大小以及CeO2和Gd2O3的晶体结构非常相似。采用混合草酸共沉淀法，在1200℃的空气中进行热分解，然后缓慢冷却，合成了x值在0 ~ 1之间的（Ce1-xGdx）O2-x/2粉末样品。采用Rietveld法对同步加速器粉末x射线衍射数据进行了采集和细化。晶格参数不遵循维加德定律，没有观察到任何组合物的峰分裂，这意味着在整个组合物范围内不存在双相区域。同样的混合结构模型——两种纯氧化物结构的适当混合——被用于细化，允许解释观察到的数据。(C) 2012爱思唯尔公司版权所有。
The structural determination of the CeO2/Gd2O3 mixed system is a non-trivial problem because of the close resemblance between the ionic sizes of Ce4+ and Gd3+ and between the crystal structures of CeO2 and Gd2O3. (Ce1-xGdx)O2-x/2 powder samples with x ranging between 0 and 1 have been synthesized by coprecipitation of mixed oxalates and subsequent thermal decomposition in air at 1200 degrees C followed by slow cooling. Synchrotron powder X-ray diffraction data were collected and refined by the Rietveld method. Lattice parameters do not follow vegard's law and no peak splitting has been observed for any composition, meaning that no biphasic regions exist over the whole compositional range. The same hybrid structural model - a proper mixture of the structures of the two pure oxides - was used for the refinements, allowing to account for the data observed. (C) 2012 Elsevier Inc. All rights reserved.