Prismatic edge dislocations in graphite
Prismatic edge dislocations in graphite
复制标题
石墨中的棱柱形刃位错
DOI：
10.1016/j.carbon.2021.11.072
复制
发表时间：
2022
期刊：
影响因子：
10.9
通讯作者：
McHugh J
中科院分区：
文献类型：
--
作者：
McHugh J
位错是材料科学中的一个核心概念，它决定了材料的塑性变形和损伤演化。石墨等层状材料中存在两种常见的层间位错：基底位错和棱柱位错，其中棱柱位错的研究相对较少。使用密度泛函理论（DFT）计算，我们已经研究了不同的棱柱形核心结构的石墨，并评估其结构，能量和流动性。我们发现密切的精力充沛的相互作用之间的结合和“独立”的核心结构在Z字形和扶手椅方向，重建稳定Z字形核心确定。我们探讨晶界和棱柱形位错堆积，确定亚稳结构，这可能是重要的能量存储。同时，对层间堆积在芯结构、位错滑移和攀移中的作用也作了深入的探讨。我们的计算表明，棱柱形位错核心是稳定的高温约1500 K的块状石墨。在此温度以上，位错核心中的键的断裂可以促进爬升、晶界运动以及通过棱柱形位错滑移的损伤退火。
Dislocations are a central concept in materials science, which dictate the plastic deformation and damage evolution in materials. Layered materials such as graphite admit two general types of interlayer dislocations:basalandprismaticdislocations, of which prismatic dislocations have been relatively less studied. Using density functional theory (DFT) calculations, we have examined different prismatic core structures in graphite and evaluated their structure, energetics and mobility. We find close energetic interplay between bonded and “free-standing” core structures in both zigzag and armchair directions, with a reconstructed stable zigzag core identified. We explore grain boundaries and prismatic dislocation pile-up, identifying metastable structures which may be important in energy storage. The role of interlayer stacking in core structure, dislocation glide and climb is also considered in-depth. Our calculations suggest that the prismatic dislocation core is stable up to high temperatures of approximately 1500 K in bulk graphite. Above this temperature, the breaking of bonds in the dislocation core can facilitate climb, grain-boundary motion, and the annealing of damage through prismatic dislocation glide.