Order-disorder phase structure, microstructure and aqueous durability of (Gd, Sm)(2)(Zr, Ce)(2)O-7 ceramics for immobilizing actinides
Order-disorder phase structure, microstructure and aqueous durability of (Gd, Sm)(2)(Zr, Ce)(2)O-7 ceramics for immobilizing actinides
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(Gd,Sm)(2)(Zr,Ce)(2)O-7固定锕系陶瓷的有序-无序相结构、显微结构及水相耐久性
DOI：
10.1016/j.ceramint.2019.06.006
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发表时间：
2019
影响因子：
5.2
通讯作者：
Liang Xiao Feng
中科院分区：
文献类型：
--
作者：
Wang Jin;Wang Jun Xia;Zhang Yi Bing;Wei Yu Feng;Zhang Kui Bao;Tan Hong Bin;Liang Xiao Feng
为了确定(Gd，Sm)_2(Zr，Ce)_2O_7陶瓷的有序-无序结构和性能，设计并制备了不同含量的Sm/Ce共掺(Gd，Sm)_2(Zr，Ce)_2O_7陶瓷。利用X射线衍射仪和拉曼光谱系统地研究了不同Sm/Ce掺杂量对样品有序-无序结构的影响。用扫描电子显微镜-能谱仪分析了样品的微观结构、元素组成和分布。通过静态浸出实验对试件的耐水性进行了评价。结果表明，不同含量的Sm/Ce可以同时取代Gd2Zr2O7焦绿石中的Gd/Zr位。随着取代后平均r[(Gd，Sm)3+]/r[(Zr，Ce)4+]半径比的降低，(Gd，Sm)2(Zr，Ce)2O7陶瓷的相结构由有序烧绿石相转变为无序缺陷-萤石相。本研究制备的陶瓷具有较高的致密性和优异的耐水性。
In this paper, to identify the order-disorder structure and performance of (Gd, Sm)2(Zr, Ce)2O7ceramic as the host matrices for immobilizing actinides, various contents of Sm/Ce co-incorporated (Gd, Sm)2(Zr, Ce)2O7ceramics were designed and fabricated. The influences of various Sm/Ce doping contents on the order-disorder structure of the samples were investigated systematically by XRD and Raman analysis. The microstructure, elemental composition and distribution of the samples were analyzed by SEM-EDX approach. The aqueous durability of the specimens was also evaluated by a static leaching experiment. The results showed that the Gd/Zr-sites of Gd2Zr2O7pyrochlore could be concurrently substituted by various contents of Sm/Ce. The phase structure of the as-prepared (Gd, Sm)2(Zr, Ce)2O7ceramics were transformed from the ordered pyrochlore phase to the disordered defect-fluorite phase with decreasing the average r[(Gd, Sm)3+]/r[(Zr, Ce)4+] radius ratio after substitution. And the ceramics fabricated in this study presented high densification and excellent aqueous durability.