Giant negative Poisson's ratio in two-dimensional V-shaped materials.

Xikui Ma,Mingwen Zhao,Yingcai Fan,Jifan Hu,Weifeng Li,Jian Liu

doi:10.1039/d1na00212k

Abstract

Two-dimensional (2D) auxetic materials with exceptional negative Poisson's ratios (NPR) are drawing increasing interest due to their potential use in medicine, fasteners, tougher composites and many other applications. Improving the auxetic performance of 2D materials is currently crucial. Here, using first-principles calculations, we demonstrated giant in-plane NPRs in MX monolayers (M = Al, Ga, In, Zn, Cd; X = P, As, Sb, S, Se, Te) with a unique V-shaped configuration. Our calculations showed that GaP, GaAs, GaSb, ZnS and ZnTe monolayers exhibit exceptional all-angle in-plane NPRs. Remarkably, the AlP monolayer possesses a giant NPR of −1.779, by far the largest NPR in 2D materials. The NPRs of these MX monolayers are correlated to the highly anisotropic features of the V-shaped geometry. The exotic mechanical properties of the V-shaped MX monolayers provide a new family of 2D auxetic materials, as well as a useful guidance for tuning the NPR of 2D materials.

Highlights

Poisson's ratio which is de ned as the ratio of lateral contraction strain to a longitudinal extension strain in the elastic loading direction serves as a fundamental parameter to quantify the mechanical properties of materials.[1]
The giant all-angle in-plane negative Poisson's ratio (NPR) in V-shaped MX monolayers opens an avenue for the design of 2D auxetic materials and provides potential for application in nanoscale electromechanical devices
We demonstrate from the rst-principles calculations the giant in-plane NPRs of the MX (M 1⁄4 Al, Zn, Ga, Cd, In; X 1⁄4 P, As, Sb, S, Se, Te) monolayers

Summary

Introduction

Poisson's ratio which is de ned as the ratio of lateral contraction strain to a longitudinal extension strain in the elastic loading direction serves as a fundamental parameter to quantify the mechanical properties of materials.[1]. The giant all-angle in-plane NPR in V-shaped MX monolayers opens an avenue for the design of 2D auxetic materials and provides potential for application in nanoscale electromechanical devices.

Results

Conclusion