Observation of the one-dimensional diffusion of nanometer-sized dislocation loops
Observation of the one-dimensional diffusion of nanometer-sized dislocation loops
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DOI：
10.1126/science.1145386
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发表时间：
2007-11-09
期刊：
影响因子：
56.9
通讯作者：
Mori, H.
中科院分区：
文献类型：
--
作者：
Arakawa, K.;Ono, K.;Mori, H.
位错是普遍存在的线性缺陷，并且是晶体材料的许多性质的原因。块体材料中位错滑移过程的研究主要集中在宏观长度的位错对外部加载或卸载的响应。使用原位透射电子显微镜，我们表明，纳米尺寸的环路与伯格斯矢量的1/2 < 111 >α-Fe可以进行一维扩散，即使在没有应力的情况下，是有效的驱动循环。回路扩散系数的回路尺寸依赖性解释的随机热波动的双扭结的数量。
Dislocations are ubiquitous linear defects and are responsible for many of the properties of crystalline materials. Studies on the glide process of dislocations in bulk materials have mostly focused on the response of dislocations with macroscopic lengths to external loading or unloading. Using in situ transmission electron microscopy, we show that nanometer-sized loops with a Burgers vector of 1/2 < 111 > in alpha-Fe can undergo one-dimensional diffusion even in the absence of stresses that are effective in driving the loops. The loop size dependence of the loop diffusivity obtained is explained by the stochastic thermal fluctuation in the numbers of double kinks.