Metadislocation core structure and atomic model for metadislocation motion
Metadislocation core structure and atomic model for metadislocation motion
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DOI：
10.1016/j.actamat.2013.03.023
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发表时间：
2013-06
期刊：
影响因子：
9.4
通讯作者：
M. Heggen;M. Feuerbacher
中科院分区：
文献类型：
--
作者：
M. Heggen;M. Feuerbacher
我们用像差校正的高分辨率电子显微镜分析了位错核的原子结构。结果表明，元位错核是高度有序的，是基于原子团簇的。它具有多尺度结构，内核包括位错的全部应变，外核不受应变，但具有相对于体积修改的簇结构。我们开发了第一个基于沿不同晶体学方向的重复跳跃模式的超位错运动的原子模型。它涉及到每一步元位错运动大约100个原子位置的移动。相邻原子列的特征平行“成对跳跃”导致原子向位错核心的净通量，这与位错运动的负爬升模式一致。
We have analyzed the atomic structure of a metadislocation core using aberration-corrected high-resolution electron microscopy. It is shown that the metadislocation core is highly ordered and based on atomic clusters. It possesses a multiscale structure with an inner core comprising the full strain of the metadislocation, and an outer core which is not strained but has a cluster structure modified with respect to the bulk. We have developed the first atomic model for metadislocation motion based on repetitive jump patterns along various crystallographic directions. It involves the movement of about 100 atomic positions per step of metadislocation motion. Characteristic parallel “paired jumps” of neighboring atomic columns lead to a net flux of atoms towards the metadislocation core which is consistent with the negative climb mode of metadislocation motion.