Abstract The solid state synthesis of the phase “Ce3NbO7+δ”, from stoichiometric quantities of CeO2 and Nb2O5, was investigated under air atmosphere, as previously described by Zhang et al. (Journal of Rare Earths, 2007, 25, 730-733). A combination of powder X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, and laboratory Ce L3 X-ray absorption spectroscopy, demonstrated the product of the reaction to be a mixture of CeO2 and CeNbO4. These data, and reexamination of the published X-ray diffraction data of “Ce3NbO7+δ”, are consistent with this phase in fact being CeO2. No evidence for the formation of a phase of composition “Ce3NbO7+δ” was found, by solid state synthesis under air atmosphere.

中文翻译：

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空气气氛下制备的化合物“Ce3NbO7+”的存在

摘要 如 Zhang 等人先前所述，在空气气氛下研究了由化学计量数量的 CeO2 和 Nb2O5 固态合成“Ce3NbO7+δ”相。（稀土杂志，2007, 25, 730-733）。粉末 X 射线衍射、带有能量色散 X 射线分析的扫描电子显微镜和实验室 Ce L3 X 射线吸收光谱的组合表明，反应产物是 CeO2 和 CeNbO4 的混合物。这些数据，以及对已发表的“Ce3NbO7+δ”X 射线衍射数据的重新检查，与该相实际上是 CeO2 相一致。在空气气氛下通过固态合成没有发现形成组成“Ce3NbO7+δ”相的证据。