Conserved Atomic Bonding Sequences and Strain Organization of Graphene Grain Boundaries
Conserved Atomic Bonding Sequences and Strain Organization of Graphene Grain Boundaries
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DOI：
10.1021/nl503450r
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发表时间：
2014-12-01
期刊：
影响因子：
10.8
通讯作者：
Zettl, Alex
中科院分区：
文献类型：
--
作者：
Rasool, Haider I.;Ophus, Colin;Zettl, Alex
多晶材料的整体性质直接受到连接相邻微晶的晶界处的原子结构的影响。在这项工作中，我们表明，石墨烯晶界是由保守的原子键合序列使用像差校正的高分辨率透射电子显微镜的结构构建块。这些序列表现为位错的相同排列的周期性或非周期性区域的延伸。原子尺度的应变和晶格旋转的这些界面是通过映射的精确位置的每个碳原子在边界处的精度。应变场被组织成局部拉伸和压缩偶极子在周期性和非周期性位错区。使用分子动力学张力模拟，我们发现，实验晶界结构保持的强度，是理想化的周期性边界，尽管存在局部非周期性位错序列。
The bulk properties of polycrystalline materials are directly influenced by the atomic structure at the grain boundaries that join neighboring crystallites. In this work, we show that graphene grain boundaries are comprised of structural building blocks of conserved atomic bonding sequences using aberration corrected high-resolution transmission electron microscopy. These sequences appear as stretches of identically arranged periodic or aperiodic regions of dislocations. Atomic scale strain and lattice rotation of these interfaces is derived by mapping the exact positions of every carbon atom at the boundary with ultrahigh precision. Strain fields are organized into local tensile and compressive dipoles in both periodic and aperiodic dislocation regions. Using molecular dynamics tension simulations, we find that experimental grain boundary structures maintain strengths that are comparable to idealized periodic boundaries despite the presence of local aperiodic dislocation sequences.