Two-dimensional arsenene polymorph beyond the auxetic foam: high mechanical sensitivity and large, negative NPR

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Single-layer δ-As and γ-P possess distinct atomic arrangements within Pmc21 and Pbcm space groups, respectively.
• Their unique coupling hinge structures lead to pronounced anisotropy in physical properties.

Purpose of the Study:

• To investigate and report the mechanical properties of single-layer δ-As and γ-P.
• To quantify their inherent negative Poisson ratio (NPR) and compare it with existing materials.

Main Methods:

• Computational analysis of mechanical properties.
• Determination of Poisson's ratio through strain simulations.

Main Results:

• Single-layer δ-As exhibits an NPR of -0.708, and γ-P shows an NPR of -0.226.
• The absolute NPR of δ-As is ~26.2 times greater than that of single-layer black phosphorus (-0.027).
• The large negative Poisson ratio of δ-As remains invariant over a specific strain range.

Conclusions:

• Single-layer δ-As demonstrates a remarkable negative Poisson ratio, significantly exceeding that of black phosphorus.
• The invariant and substantial negative Poisson ratio of δ-As suggests significant potential for applications in nanosensors and electronic wearable devices.