Emergent Structure of Multidislocation Ground States in Curved Crystals
Emergent Structure of Multidislocation Ground States in Curved Crystals
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DOI：
10.1103/physrevlett.112.225502
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发表时间：
2014-06-04
影响因子：
8.6
通讯作者：
Grason, Gregory M.
中科院分区：
文献类型：
--
作者：
Azadi, Amir;Grason, Gregory M.
我们研究了晶体球冠的多位错基态的结构特征和基本原理。在晶体尺寸与晶格间距的比率W/a发散的连续极限中，位错增殖并且基态接近由径向晶界（“中性疤痕”）组成的结构的特征序列，所述径向晶界从边界径向延伸并且终止于本体中。采用数值模拟和连续弹性理论的渐近分析相结合，我们证明了一个充满活力的层次结构，从而位错数和疤痕数发散为a/W -> 0，而疤痕长度和位错数每疤痕成为独立的晶格间距。我们的特征在于疤痕长度的增长，其中的n-倍疤痕对称性被打破，基态的特点是多分散，分叉疤痕形态发生的二次过渡。
We study the structural features and underlying principles of multidislocation ground states of a crystalline spherical cap. In the continuum limit where the ratio of crystal size to lattice spacing W/a diverges, dislocations proliferate and ground states approach a characteristic sequence of structures composed of radial grain boundaries ("neutral scars"), extending radially from the boundary and terminating in the bulk. Employing a combination of numerical simulations and asymptotic analysis of continuum elasticity theory, we prove that an energetic hierarchy gives rise to a structural hierarchy, whereby dislocation number and scar number diverge as a/W -> 0 while scar length and dislocation number per scar become independent of lattice spacing. We characterize a secondary transition occurring as scar length grows, where the n-fold scar symmetry is broken and ground states are characterized by polydisperse, forked-scar morphologies.