摘要:
以具有较强抗辐照和化学稳定性的锆基烧绿石Nd2Zr2O7为固化基材，针对锕系核素U进行固化研究。以硝酸盐作为原料，通过柠檬酸络合和喷雾热解的方法，在1200℃保温12 h成功制备了含U 10 mol%的烧绿石固化体。产物经X-射线粉末衍射、拉曼光谱进行表征，结果表明：U很好的包容到烧绿石固化体中，固化体保持单一的烧绿石结构；U离子半径小于Nd，导致固化体晶格常数减小；随着U成分的增加，固化体的烧绿石结构趋向于无序化。
Abstract: The solubility of Uranium in pryochlore Nd2Zr2O7 has been studied using zirconate pyrochlores as potential material for use in the high level nuclear waste because of their chemical and radi- ation stabilities. Uranium-doped Pyrochlore Nd1.9U0.1Zr2O7 was synthesized at 1200˚C for 12 h by sol-spray pyrolysis method using nitrate and citrate acid as raw materials. The phase compositions of the products were characterized by powder XRD, SEM, Raman spectrum. The results reveal that Uranium has been incorporated in the lattice of Nd2Zr2O7, while maintaining the single pyrochlore structure. The lattice parameter decreases for Nd2Zr2O7 pyrochlore with increase in Uranium content because the effective ionic radius of U is less than that of Nd3+. With increasing Uranium content, the degree of crystal structural disorder increases.