摘要
为研究超化学剂量二氧化铀(UO2+x)中缺陷对烧结的影响,应用缺陷化学理论建立了点缺陷模型(PDM)。通过PDM计算了UO2+x中的缺陷浓度、铀离子的扩散系数、烧结后密度等。结果表明,二氧化铀中的铀离子和氧离子的缺陷浓度随着气氛中氧分压(pO2)或UO2+x中的多余氧x的变化而急剧变化。超化学剂量二氧化铀芯块的烧结试验结果很好地符合了计算值。PDM揭示了UO2+x粉末能够在较低温度下烧结成芯块的机理。
The point defect model （PDM） of hyper-stoichiometry uranium dioxide was built for studying the effective of defects to sintering. According to PDM, the reaction equations and the concentrations of defects were found out. The concentrations of defects are dramatically different with the change of partial pressure of oxygen （pO2） or excess oxygen ions （x in UO2＋x）. The PDM is used to calculate diffusion coefficient of uranium ions and sintering density of UO2＋x pellets, the experimental results agree the calculated results quite well. PDM explains the mechanism of low temperature sintering to UO2＋x powder.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2009年第10期877-880,共4页
Atomic Energy Science and Technology
基金
国家自然科学基金资助项目(50874126)
关键词
点缺陷模型
超化学剂量
反应方程
缺陷浓度
扩散系数
point defect model
hyper-stoichiometry
reaction equation
defect concentration
diffusion coefficient
