Elastic properties and sound velocities of silicane/graphane hybrids

Abstract

Using ab initio density functional theory, the effect of hydrogen arrangement on the elastic properties of silicene–graphene hybrid is studied. Mechanical stability, elastic constants and sound velocities of pure and five configurations of hydrogenated SiC sheet, namely, chair, table, boat, zigzag and armchair, are explicitly examined. To reveal the anisotropic properties of the six structures, the polar plots of Young’s modulus, Poisson ratio and acoustic waves speed are given. Compared to graphene, it is shown that all the isotropic systems are less stiffer with lower in-plane Young’s modulus and stronger with their larger Poisson ratio, moreover, their compressional and shear waves propagate faster. The analysis of linear elastic behavior shows that the armchair configuration has an auxetic structure. The result of this work could be used for the design of future silicane–graphane based nanodevices with potentially large technological impact in nanomechanics.