The elastic properties and deformation behaviors of edges in the free-standing one-atom-thick silicon-carbide nanoribbons (SiCNR) are studied using atomistic simulations. Edge energy and edge stress are calculated by quantum mechanical first-principles calculations based on the density-functional theory and by energy minimization with the Tersoff silicon-carbide empirical interatomic potential. Two types of edges, armchair and zigzag according to the edge atomic structure of SiCNR, are considered in this study. It is found that both types of edges are in compression along the edge direction, but their deformation behaviors are very distinct. By performing constant-temperature molecular dynamics simulation, we further show that the physical origin of these different elastic behaviors is the different atomic structures in the vicinity of edges. Edge stress of zigzag SiCNR is also calculated under anti-ferromagnetic ground state and compared with the one under paramagnetic ground state. Edge energies of hydrogen-passivated SiCNR are calculated in order to investigate effect of hydrogen termination on the stability of SiCNR.
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