Elastic fields and moduli in defected graphene
Elastic fields and moduli in defected graphene
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DOI：
10.1088/0953-8984/24/10/104020
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发表时间：
2012-03-14
影响因子：
2.7
通讯作者：
Colombo, Luciano
中科院分区：
文献类型：
--
作者：
Dettori, Riccardo;Cadelano, Emiliano;Colombo, Luciano
通过紧束缚原子模拟，我们研究了最近在实验中发现的石墨烯中的一系列原生缺陷。它们的形成能被发现是几个电子伏大，与大多数石墨烯样品中的高结晶质量的经验证据一致。缺陷，特别是如果与债券重建，诱导相当大的变形和应力场的空间分布密切相关的实际对称性。这里提出的这些领域的描述被认为是有用的电子显微镜获得的图像的明确表征。我们还认为，它们定义了两个附近的缺陷之间的相互作用的盆地。最后，我们提供的证据表明，缺陷不同地影响单层石墨烯的线弹性模量。在一般情况下，无论是杨氏模量和泊松比下降，但它们对缺陷表面密度的依赖性是显着更明显的空位比数样缺陷。
By means of tight-binding atomistic simulations we study a family of native defects in graphene which have recently been detected experimentally. Their formation energy is found to be as large as several electronvolts, consistent with the empirical evidence of high crystalline quality in most graphene samples. Defects, especially if associated with bond reconstructions, induce sizable deformation and stress fields with a spatial distribution closely related to their actual symmetry. The description of such fields proposed here is believed to be useful for the unambiguous characterization of images obtained by electron microscopy. We also argue that they define the basin of mutual interaction between two nearby defects. Finally, we provide evidence that defects differently affect the linear elastic moduli of monolayer graphene. In general, both the Young modulus and the Poisson ratio are decreased, but their dependence upon the defect surface density is remarkably more pronounced for vacancy-like than for number-like defects.