A MECHANISM FOR THE UO2 TO ALPHA-U3O8 PHASE-TRANSFORMATION

被引：68
作者：
ALLEN, GC [1 ]
HOLMES, NR [1 ]
机构：
[1] BP CHEM LTD,WORKS LAB,GRANGEMOUTH,SCOTLAND
来源：
JOURNAL OF NUCLEAR MATERIALS | 1995年 / 223卷 / 03期
关键词：
D O I：
10.1016/0022-3115(95)00025-9
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The UO2 fluorite structure transforms to the layered structure of alpha-U3O8 by a displacement of the (111) planes in UO2. In the first step the ABCABC packing sequence of the uranium layers in the UO2 structure is changed to an AA sequence for the outermost layers at the (111) face. This occurs through a displacement of 2.23 Angstrom along a [112] direction in the (111) plane, to bring the outermost uranium layer directly above the second layer. To form alpha-U3O8 the outermost uranium layer must expand upwards by 0.99 Angstrom in the [111] direction perpendicular to these planes to give the correct interplanar spacing and to allow the incorporation of the oxygen atoms which form the uranium-oxygen-uranium chains in alpha-U3O8.
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页码：231 / 237
页数：7
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