The effects of uranium on the structure of iron phosphate glasses
The effects of uranium on the structure of iron phosphate glasses
复制标题
铀对磷酸铁玻璃结构的影响
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. Ray
中科院分区：
文献类型：
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作者：
Y. Badyal;M. Karabulut;K. Marasinghe;M. Saboungi;D. Haeffner;S. Shastri;D. Day;C. Ray
由于其高化学耐久性和废物装载能力，铁磷酸盐玻璃是核废物处理介质的天然候选者。作者用中子衍射和高能x射线衍射研究了铀对铁磷酸盐玻璃结构的影响。中子散射的结果，这是最敏感的对关联涉及轻原子，即，O-O、Fe-O和P-O等结构特征表明，UO{sub 2}的加入对基础玻璃的主要结构特征基本没有影响。在真实的空间中，最近邻的P-O、Fe-O和O-O峰保持在相同的位置，并且它们的强度与浓度近似成比例。这些发现是一致的早期结果，使用拉曼散射和EXAFS的Fe-K边缘，在这两种情况下，光谱保持类似的基础玻璃。高能X射线散射的结果，这是敏感的相关性，涉及较重的原子，从而补充了中子测量，也是一致的整体图片的铀占据间隙网站在相对未受干扰的基础玻璃结构。结合10 mol% UO{sub 2}玻璃的中子和X射线数据，表明U{sup 6+}铀酰离子构型的有趣可能性，尽管需要进一步的工作来建立这些玻璃中铀的精确局部结构和价态。«少
Because of their high chemical durability and waste loading capacity, iron phosphate glasses are a natural candidate for a nuclear waste disposal medium. The authors have studied the effects of uranium on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction. The results of neutron scattering, which is mostly sensitive to pair correlations involving light atoms, i.e., O-O, Fe-O and P-O, indicate the main structural features of the base glass are largely unaffected by the addition of UO{sub 2}. The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with earlier results using Raman scattering and EXAFS on the Fe-K edge, where in both cases the spectra remain similar to the base glass. The results of high-energy x-ray scattering, which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, are also consistent with the overall picture of uranium occupying interstitial sites in the relatively undisturbed base glass structure. Combining the neutron and x-ray data for a 10 mol% UO{sub 2} glass suggests the intriguing possibility of a U{sup 6+} uranyl ion configuration although further workmore » is needed to establish the precise local structure and valence state of uranium in these glasses.« less