A compositional and structural rationalization of the higher oxides of Ce, Pr, and Tb
A compositional and structural rationalization of the higher oxides of Ce, Pr, and Tb
复制标题
DOI：
10.1016/s0925-8388(96)02633-3
复制
发表时间：
1997-03
影响因子：
6.2
通讯作者：
Z. Kang;L. Eyring
中科院分区：
文献类型：
--
作者：
Z. Kang;L. Eyring
铈、镨、铽是一类与萤石有关的混合价二元氧化物。最近从中子衍射数据中对该系列的五个成员进行了结构改进，首次概括了它们结构的主要特征，并提出了一个结构原理以及一个通用公式，涵盖了所有已知的同源系列成员及其多晶型物。结构原理还允许正确地对五种精细结构进行建模（并且被认为是唯一的），因此，可以可靠地预测尚未确定的系列成员的结构，其中组合物和合适的衍射图案可用。其原理来自于可能含有空氧位点的萤石单元电池模块可以组装在一起的方式。这些模块的包装规则和他们的应用程序的例子。
Cerium, praseodymium and terbium exhibit a family of related mixed-valent binary oxides which are anion-deflcient and fluorite-related. The recent structural refinement of five members of this series from neutron diffraction data have made it possible for the first time to generalize the main features of their structures, and to propose a structural principle as well as a generic formula covering all known members of the homologous series and their polymorphs. The structural principle also permits the modeling of the five refined structures correctly (and it is believed uniquely), hence, the confident prediction of the, as yet undetermined, structures of series members for which the composition and suitable diffraction patterns are available. The principle flows from the way fluorite unit-cell modules which may contain vacant oxygen sites can pack together. Rules for packing these modules and examples of their application are presented.