First-principles investigation of mechanical properties of silicene, germanene and stanene

TL;DR

This study uses first-principles calculations to analyze the mechanical properties of silicene, germanene, and stanene, revealing how uniaxial loading affects their stress-strain behavior and electronic properties.

Contribution

It provides a comparative first-principles analysis of the mechanical and electronic responses of silicene, germanene, and stanene under uniaxial stress, including chirality effects.

Findings

Uniaxial loading can turn buckled structures metallic.

Young's modulus and Poisson ratio vary with chirality.

Mechanical properties differ among silicene, germanene, and stanene.

Abstract

Two dimensional allotropes of group IV substrates including silicene, germanene and stanene have recently attracted considerable attention in nanodevice fabrication industry. These materials involving the buckled structure have been experimentally fabricated lately. In this study, first principles density functional theory calculations were utilized to investigate the mechanical properties of single layer and free standing silicene, germanene and stanene. Uniaxial tensile and compressive simulations were carried out to probe and compare stress strain properties; such as the Young modulus, Poisson ratio and ultimate strength. We evaluated the chirality effect on the mechanical response and bond structure of the 2D substrates. Our first principles simulations suggest that in all studied samples application of uniaxial loading can alter the electronic nature of the buckled structures into the metallic character. Our investigation provides a general but also useful viewpoint with respect to the mechanical properties of silicene, germanene and stanene.