Electron microscope observations of irradiated graphite single crystals
Electron microscope observations of irradiated graphite single crystals
复制标题
辐照石墨单晶的电子显微镜观察
DOI：
10.1016/0008-6223(64)90015-6
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发表时间：
1964
期刊：
影响因子：
10.9
通讯作者：
G. Hennig
中科院分区：
文献类型：
--
作者：
W. Bollmann;G. Hennig
在低于 150°C 的温度下用 5.2×l017 至 1.5×1020n/cm2 的快中子辐照后，通过暗场透射电子显微镜研究了石墨单晶。已研究了高达 2000°C 的后续退火。为了进行比较，我们研究了电子、C12 离子和裂变碎片辐照的样本。通过电子衍射运动学理论计算了对比度效应。通过表面蚀刻和表面装饰技术研究了空位的分布。所有观察结果都与独立间隙和空位的主要形成以及随后仅间隙的聚集的假设相一致。这些团簇中只有一小部分可以通过电子显微镜分辨出来；它们含有大约 1% 的最初被置换的原子。当剂量高于 1020n/cm2 时，会观察到更复杂的现象。
Graphite single crystals have been studied by dark field transmission electron microscopy after irradiation with fast neutrons between 5.2×l017and 1.5×1020n/cm2at temperatures below 150°C. Subsequent annealing has been investigated up to 2000°C. For comparison, specimens irradiated by electrons, C12-ions and fission fragments have been studied. Contrast effects have been calculated by means of the kinematical theory of electron diffraction. The distribution of vacancies was studied by a surface etch and surface decoration technique. All the observations are compatible with the assumption of the primary formation of independent interstitials and vacancies and subsequent clustering of only the interstitials. Only a small fraction of these clusters can be resolved by electron microscopy; these contain about 1 per cent of the originally displaced atoms. At a dose above 1020n/cm2more complex phenomena are observed.