| 金属铀表面氧化动力学的X射线衍射研究 |
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| 引用本文： | 张延志,管卫军,帅茂兵,汪小琳,赖新春,王勤国. 金属铀表面氧化动力学的X射线衍射研究[J]. 原子能科学技术, 2006, 40(5): 529-533. DOI: 10.7538/yzk.2006.40.05.0529 |
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| 作者姓名： | 张延志 管卫军 帅茂兵 汪小琳 赖新春 王勤国 |
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| 作者单位： | 表面物理和化学国家重点实验室，四川 ;绵阳 621907 |
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| 基金项目： | 中国工程物理研究院基金课题资助项目(20030330) |
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| 摘 要： | 利用X射线衍射和Rietveld方法研究室温～150℃和300℃下金属铀表面氧化，对氧化过程中试样的表面结构以及氧化动力学进行分析。将试样表面氧化物随时间的变化作定量计算，绘制出不同温度下金属铀表面的氧化动力学曲线，对50～150℃范围内的氧化动力学数据进行拟合，获得不同温度下的氧化反应速率常数，由此得到大气环境下金属铀表面形成UO2的活化能为46.0kJ/mol。在300℃下，氧化产物U3O8逐渐在UO2上形成，其形成过程符合成核生长机理。
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| 关 键 词： | 金属铀 动力学 X射线衍射 Rietveld方法 |
| 文章编号： | 1000-6931（2006）05-0529-05 |
| 收稿时间： | 2005-01-25 |
| 修稿时间： | 2005-01-252005-08-25 |
Dynamics Study on Surface Oxidization of Uranium by X-ray Diffraction |
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| ZHANG Yan-zhi,GUAN Wei-jun,SHUAI Mao-bing,WANG Xiao-lin,LAI Xin-chun,WANG Qin-guo. Dynamics Study on Surface Oxidization of Uranium by X-ray Diffraction[J]. Atomic Energy Science and Technology, 2006, 40(5): 529-533. DOI: 10.7538/yzk.2006.40.05.0529 |
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| Authors: | ZHANG Yan-zhi GUAN Wei-jun SHUAI Mao-bing WANG Xiao-lin LAI Xin-chun WANG Qin-guo |
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| Affiliation: | National Key Laboratory for Surface Physics and Chemistry, P.O.Box 718-35, Mianyang 621907, China |
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| Abstract: | he oxidation of uranium metal was studied by X-ray diffraction(XRD) and Rietveld method in the range of 25-150 ℃ and at 300 ℃, respectively. The processes of oxidation to UO2 and U3O8 were analyzed by XRD in order to observe the extent of surface oxidation and the oxide structure. The dynamics expression for the formation of UO2 in the temperature range of 25-150 ℃ was initially nonlinear, but switched to linear at long reaction time, that is, there exist two stages in the UO2 growth kinetics: nonlinear portion and linear portion. Using the kinetic data of linear portion the activation energy of oxidation is obtained to be about 46.0 kJ/mol. The U3O8 forms gradually on UO2 layer at 300 ℃, which accords with the nucleation-and-growth kinetics mechanism. |
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| Keywords: | uranium oxidation kinetics X-ray diffraction Rietveld method |
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