Grain Boundaries in Uranium Dioxide: Scanning Electron Microscopy Experiments and Atomistic Simulations
Grain Boundaries in Uranium Dioxide: Scanning Electron Microscopy Experiments and Atomistic Simulations
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DOI：
10.1111/j.1551-2916.2010.04295.x
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发表时间：
2011-06-01
影响因子：
3.9
通讯作者：
Stanek, Christopher R.
中科院分区：
文献类型：
--
作者：
Nerikar, Pankaj V.;Rudman, Karin;Stanek, Christopher R.
对UO(2)中晶界的分布和原子结构进行了研究。我们对贫化 UO(2) 样品进行的扫描电子显微镜/电子背散射衍射实验表明，真正的核燃料包含特殊重合位点晶格 (CSL) 和一般边界的组合。实验数据表明，相似的16%的边界是CSL边界，并且CSL分布以低Sigma边界为主；即 Sigma 9、Sigma 3 和 Sigma 5 根据我们的实验观察，使用经验势原子尺度计算对选定的低 Sigma（Sigma 5 倾斜、Sigma 5 扭曲、Sigma 3 倾斜）和随机边界的结构进行了更详细的分析。我们的计算表明，边界具有非常不同的结构，并且每个 CSL 边界在伽马表面上都有多个最小值。大部分 CSL 边界的存在及其结构的差异预计会对燃料特性产生重要影响。
The distribution and atomic structure of grain boundaries has been investigated in UO(2). Our scanning electron microscopic/electron backscatter diffraction experiments on a depleted UO(2) sample showed real nuclear fuels contain a combination of special coincident site lattice (CSL) and general boundaries. The experimental data indicated that similar to 16% of the boundaries were CSL boundaries and the CSL distribution was dominated by low Sigma boundaries; namely Sigma 9, Sigma 3, and Sigma 5 Based on our experimental observations, the structures of select low Sigma (Sigma 5 tilt, Sigma 5 twist, Sigma 3 tilt) and a random boundary were analyzed in greater detail using empirical potential atomic-scale calculations. Our calculations indicate that the boundaries have very different structures and each CSL boundary had multiple minima on the gamma-surface. The presence of a significant fraction of CSL boundaries and the differences in their structures are expected to have important consequences on fuel properties.