Excess energy and deformation along free edges of graphene nanoribbons
Excess energy and deformation along free edges of graphene nanoribbons
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DOI：
10.1103/physrevb.81.155410
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发表时间：
2009-10
影响因子：
3.7
通讯作者：
Q. Lu;Rui Huang
中科院分区：
文献类型：
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作者：
Q. Lu;Rui Huang
石墨烯单层的自由边缘处的键合环境的变化导致过量的边缘能量和边缘力，这取决于边缘形态（锯齿形或扶手椅形）。通过使用一个反应的经验键序势和原子模拟，我们表明，多余的边缘能量在独立的石墨烯纳米带可以部分放松的面内和面外变形。计算了具有平行锯齿形和扶手椅形边缘的石墨烯纳米带的过剩边缘能和边缘力。取决于纵向约束，压缩边缘力导致带的面内伸长或面外屈曲变形。在前一种情况下，纵向应变与带宽度成反比。在后一种情况下，能量最小化预测的边缘屈曲的固有波长为6.2 nm沿着的锯齿形边缘和8.0 nm沿着的扶手椅边缘。对于宽度小于本征波长的石墨烯纳米带，两个自由边缘之间的相互作用变得显著，导致屈曲波的反相关联。
Change in the bonding environment at the free edges of graphene monolayer leads to excess edge energy and edge force, depending on the edge morphology (zigzag or armchair). By using a reactive empirical bond-order potential and atomistic simulations, we show that the excess edge energy in free-standing graphene nanoribbons can be partially relaxed by both in-plane and out-of-plane deformation. The excess edge energy and edge force are calculated for graphene nanoribbons with parallel zigzag or armchair edges. Depending on the longitudinal constraint, the compressive edge force leads to either in-plane elongation of the ribbon or out-of-plane buckling deformation. In the former case, the longitudinal strain is inversely proportional to the ribbon width. In the latter case, energy minimization predicts an intrinsic wavelength for edge buckling to be 6.2 nm along the zigzag edge and 8.0 nm along the armchair edge. For graphene nanoribbons of width less than the intrinsic wavelength, interaction between the two free edges becomes significant, leading to antiphase correlation of the buckling waves.