We have observed the development of cascade defects formed by irradiation with 400 keV Cu⁺ ions in high-purity Cu at 50 K, and demonstrated the one-dimensional motion of freely or sporadically migrating small defect clusters during post annealing, using in-situ electron microscopy. The diffusivity for the back-and-forth one-dimensional motion of the freely migrating clusters during the post annealing at 50 K was evaluated based on the random walk theory. The free migration distance during the sporadic 1-D motion of the small clusters decreased with increasing the fluence of irradiated ions, which suggests trapping sites of radiation-induced defects. A significant number of cascade induced defects changed their positions and shapes at 50 K, and were annihilated by post annealing at 100 or 150 K. The present results for the free or sporadic 1-D motion of small defect clusters have a great impact on the current understanding of defect recoveries in stages I_D+E and II for fcc metals.

我们已经观察到在高纯铜中在50 K下用400 keV的Cu ⁺离子辐照形成的级联缺陷的发展，并证明了在后退火过程中使用原位自由或偶发迁移的小缺陷簇的一维运动。电子显微镜。基于随机游走理论，评估了50 K后退火过程中自由迁移簇的来回一维运动的扩散性。小簇的零星一维运动过程中的自由迁移距离随着辐照离子通量的增加而减小，这暗示了由辐射引起的缺陷的俘获位点。大量的级联缺陷在50 K时改变了它们的位置和形状，并在100或150 K下通过后退火消除了。小缺陷簇的自由或偶发一维运动的当前结果对材料的缺陷有很大的影响。当前对fcc金属的I _{D + E}和II阶段的缺陷恢复的了解。