Negative Poisson's ratios in few-layer orthorhombic arsenic from first-principles calculations

TL;DR

This study predicts and explains the layer-dependent negative Poisson's ratio in orthorhombic arsenic using first-principles calculations, revealing its potential for advanced material applications.

Contribution

It introduces a new 2D material with negative Poisson's ratio and elucidates the layer-dependent mechanism behind this property.

Findings

Monolayer arsenic has a negative Poisson's ratio of about -0.09.

Negative Poisson's ratio becomes more negative with increasing layers.

The bulk arsenic's Poisson's ratio is approximately -0.12.

Abstract

A material exhibiting a negative Poisson's ratio is always one of the leading topics in materials science, which is due to the potential applications in those special areas such as defence and medicine. In this letter, we demonstrate a new material, few-layer orthorhombic arsenic, also possesses the negative Poisson's ratio. For monolayer arsenic, the negative Poisson's ratio is predicted to be around -0.09, originated from the hinge-like structure within the single layer of arsenic. When the layer increases, the negative Poisson's ratio becomes more negative and finally approaches the limit at four-layer, which is very close to the bulk's value of -0.12. The underlying mechanism is proposed for this layer-dependent negative Poisson's ratio, where the internal bond lengths as well as the normal Poisson's ratio within layer play a key role. The study like ours sheds new light on the physics of negative Poisson's ratio in those hinge-like nano-materials.