Nd and Ce simultaneous substitution driven structure modifications in Gd2−xNdxZr2−yCeyO7
Nd and Ce simultaneous substitution driven structure modifications in Gd2−xNdxZr2−yCeyO7
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DOI：
10.1016/j.jeurceramsoc.2014.12.017
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发表时间：
2015-06
影响因子：
5.7
通讯作者：
Sijin Su;Yi Ding;X. Shu;Hui Dan;H. Tu;F. Dong;Xirui Lu
中科院分区：
文献类型：
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作者：
Sijin Su;Yi Ding;X. Shu;Hui Dan;H. Tu;F. Dong;Xirui Lu
采用简单固相法合成了单相Gd2−xNdxZr2−yCeyO7（0≤x,y≤2）陶瓷。首次系统地研究了钕和铈同时取代对结构修饰的影响。利用x射线衍射证实采用了焦绿石或萤石结构。XRD结果表明，同时取代引起的结构修饰强烈依赖于Nd和Ce的溶解度。结果表明，从gd0.4 nd1.6 zr2o7到Nd2Zr1.6Ce0.4O7，在1.6≤x≤2,0≤y≤0.4的范围内，样品保持有序的焦绿石结构。而从gd2zr1.2 ce0.8 o7到Nd2Ce2O7，在0≤x≤2,0.8≤y≤2的条件下，样品失去了有序的焦绿石结构，结构转变为萤石。此外，在Gd3+和Zr4+位置，Gd3+和Zr4+全部可以分别被Nd3+和Ce4+取代，其端元nd2ce2o7为萤石结构。研究确定了具有单相结构的Gd2−xNdxZr2−yCeyO7（0≤x,y≤2）连续范围的存在。
Single phase Gd2−xNdxZr2−yCeyO7(0 ≤x,y≤ 2) ceramics were synthesized by a simple solid-state reaction method. The neodymium and cerium simultaneous substitution influence on the structure modifications were first investigated systematically. X-ray diffraction has been utilized to confirm adoption of pyrochlore or fluorite structure. XRD results show that structure modifications induced by simultaneous substitution are strongly dependent on the solubility of both Nd and Ce. It was found that the ordered pyrochlore structure was maintained for samples with 1.6 ≤x≤ 2, 0 ≤y≤ 0.4, from Gd0.4Nd1.6Zr2O7to Nd2Zr1.6Ce0.4O7. Whereas, the ordered pyrochlore structure was lost for samples with 0 ≤x≤ 2, 0.8 ≤y≤ 2, from Gd2Zr1.2Ce0.8O7to Nd2Ce2O7, and the structure transformed to fluorite. Furthermore, at the Gd3+and Zr4+positions, the whole of Gd3+and Zr4+could be replaced by Nd3+and Ce4+, respectively, with its end member Nd2Ce2O7was fluorite structure. The studies established the existence of a continuous range of Gd2−xNdxZr2−yCeyO7(0 ≤x,y≤ 2) ceramics with a single phase structure.