Chávez-Castillo M R, Rodríguez-Meza M A, Meza-Montes L
Instituto de Física, Benemérita Universidad Autónoma de Puebla Apdo. Postal J-48 72570 Puebla Pue. Mexico
Instituto Nacional de Investigaciones Nucleares Apdo. Postal 18-1027 11801 México, D.F. Mexico.
RSC Adv. 2018 Mar 19;8(20):10785-10793. doi: 10.1039/c7ra12482a. eCollection 2018 Mar 16.
Understanding the behaviour of nanoscale systems is of great importance to tailor their properties. To this aim, we investigate the Young's modulus (YM) of defect-free and defective armchair bilayer silicene nanoribbons (SNRs), at room temperature, as a function of length and distance between layers. In this study, we perform molecular dynamics simulations using the environment-dependent interatomic potential to describe the interaction of the Si atoms. We show that the Young's modulus of pristine and defective bilayer SNRs increases with the ribbon length exhibiting size dependence. In general, YM of defective bilayer SNRs is smaller than the value obtained for the defect-free case, as a result of the number of missing bonds. In all cases, as the interlayer distance increases YM decreases and the buckling increases. It is shown that the YM exhibits a quadratic interlayer distance dependence. Finally, when only one layer has a mono-vacancy defect, the atomic stress distribution of the pristine layer is affected by the presence of the vacancy. This effect can be considered as a "ghost vacancy" since the deterioration of the pristine layer is similar to that shown by the defective one. These results show that YM of pristine and defective bilayer SNRs could be tailored for a given length and interlayer distance. It is also found that the fracture stress and the fracture strain of defective bilayers are both smaller than those obtained for the defect-free ones.
了解纳米尺度系统的行为对于调整其性能至关重要。为此，我们研究了在室温下无缺陷和有缺陷的扶手椅型双层硅烯纳米带（SNR）的杨氏模量（YM），作为长度和层间距离的函数。在本研究中，我们使用与环境相关的原子间势进行分子动力学模拟，以描述硅原子之间的相互作用。我们表明，原始和有缺陷的双层SNR的杨氏模量随带长增加而增大，呈现出尺寸依赖性。一般来说，由于缺失键的数量，有缺陷的双层SNR的YM小于无缺陷情况下的值。在所有情况下，随着层间距离增加，YM减小且屈曲增加。结果表明，YM呈现二次方的层间距离依赖性。最后，当只有一层存在单空位缺陷时，原始层的原子应力分布会受到空位存在的影响。这种效应可被视为“虚拟空位”，因为原始层的劣化与有缺陷层的情况相似。这些结果表明，对于给定的长度和层间距离，可以调整原始和有缺陷的双层SNR的YM。还发现有缺陷双层的断裂应力和断裂应变均小于无缺陷双层的相应值。
