Mechanical properties of silicene

The potential of atomistically two-dimensional (2D) materials has created a new paradigm of materials science. Among the various 2D crystalline structures is silicene – a monolayer allotrope of silicon – similar to the structure of graphene. While this material has been previous investigated for potential in electrical applications, successful implementation in such nanodevices requires full understanding of its mechanical behavior. Here, using full atomistic first-principles-based ReaxFF molecular dynamics (MD) we quantify the elastic stiffness (50.44 N/m for zigzag direction, 62.31 N/m for armchair direction) and limit states (ultimate strength on the order of 5.85 N/m, ultimate strain on the order of 18%) of monolayer silicene. A weak directional dependence is observed. Moreover, we quantify the effective bending stiffness of silicene (38.63 eV per unit width), indicating that its corrugated-like structure increases the bending rigidity compared to the similar system of graphene.