Qi Ni , Congcong Ding , Fuxin Liu , Fen Luo , Xiaoyan Shu , Yulu Fu , Xirui Lu
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引用次数: 0
Abstract
Multi-component high-entropy pyrochlore (HEP) offers several advantages compared to single-component pyrochlore in solidifying radioactive waste, including the ability to solubilize multiple types of waste and lower leaching rates (LRs) of radionuclides. In this study, we successfully synthesized HEP (Y0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 and immobilized Ce, a simulated nuclide of Pu at 1500 °C for 48 h using a free occupied design approach. The Raman, XRD, and Rietveld refinement results showed that the immobilization limit for Ce fell between 20 wt.% and 30 wt.%. Notably, the ordered pyrochlore phase gradually transformed into the defective fluorite phase with an increase in Ce content. Moreover, the leaching tests demonstrated the excellent stability of the matrix, with the normalized LR for Ce reaching 10−7 g·m−2·L−1 after 42 days at 90 °C. These findings collectively suggest that HEP (Y0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 holds promise as a substrate for immobilizing radioactive waste in the future.
与单组分热长岩相比，多组分高熵热长岩（HEP）在固化放射性废物方面具有多种优势，包括能够溶解多种类型的废物和降低放射性核素的浸出率（LRs）。在本研究中，我们成功合成了 HEP (Y0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7，并采用自由占位设计方法在 1500 °C 下固定了钚的模拟核素 Ce 48 小时。拉曼、X 射线衍射和里特维尔德精炼结果表明，Ce 的固定极限在 20 wt.% 到 30 wt.% 之间。值得注意的是，随着 Ce 含量的增加，有序的热绿石相逐渐转变为有缺陷的萤石相。此外，浸出测试表明基质具有出色的稳定性，在 90 °C 下浸出 42 天后，Ce 的归一化 LR 达到 10-7 g-m-2-L-1。这些发现共同表明，HEP (Y0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7有望成为未来固定放射性废物的基质。
期刊介绍：
The Journal of the European Ceramic Society publishes the results of original research and reviews relating to ceramic materials. Papers of either an experimental or theoretical character will be welcomed on a fully international basis. The emphasis is on novel generic science concerning the relationships between processing, microstructure and properties of polycrystalline ceramics consolidated at high temperature. Papers may relate to any of the conventional categories of ceramic: structural, functional, traditional or composite. The central objective is to sustain a high standard of research quality by means of appropriate reviewing procedures.
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