Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Mumbai, India.
Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
J Hazard Mater. 2021 Jun 5;411:125025. doi: 10.1016/j.jhazmat.2020.125025. Epub 2021 Jan 3.
NaEu:Ca(PO)F is explored as a potential host for radioactive waste immobilization. Since Eu ion is a surrogate of highly radioactive Am ion, the photoluminescence (PL) characteristics of Eu ion helped to investigate the possible distribution of hazardous and radioactive Am ion among the two lattice sites in the matrix. It was observed that Am will prefer to occupy the Ca2-site lattice which has a direct linkage to F atom. From DFT calculation we have found that both Eu and Am ions are following similar trend of distribution into the Ca2-site compared to Ca1-site which has no F atom linkage. The radiation stability of the compound was also investigated by PL study after irradiating it with a Co gamma source with different doses starting from 2 kGy to as high as 1000 kGy. It was observed that radiation induced changes were more surrounding the Ca1-site than in Ca2-site.Considering all the experimental and theoretical observations it is concluded that from radioactive waste immobilization point of view it is more preferable to dope the Am ion into the Ca2 site. The Eu doped compound was also found to be red color emitting phosphor materials with color purity of 95.24%.
NaEu:Ca(PO)F 被探索用作放射性废物固化的潜在宿主。由于 Eu 离子是高放射性 Am 离子的替代物，Eu 离子的光致发光（PL）特性有助于研究危险和放射性 Am 离子在基质中两个晶格位置之间的可能分布。观察到 Am 将优先占据与 F 原子直接相连的 Ca2-位晶格。通过 DFT 计算，我们发现与没有 F 原子连接的 Ca1-位相比，Eu 和 Am 离子在 Ca2-位的分布趋势相似。还通过用 Co 伽马源在从 2 kGy 到高达 1000 kGy 的不同剂量下辐照后进行 PL 研究，研究了化合物的辐射稳定性。观察到辐射诱导的变化主要发生在 Ca1-位周围，而不是 Ca2-位。考虑到所有实验和理论观察结果，从放射性废物固化的角度来看，将 Am 离子掺杂到 Ca2-位更可取。还发现 Eu 掺杂的化合物是红色发射荧光粉材料，颜色纯度为 95.24%。
