Effects of intrinsic strain on the structural stability and mechanical properties of phosphorene nanotubes

TL;DR

This study uses molecular dynamics simulations to investigate how intrinsic strain affects the stability and mechanical properties of phosphorene nanotubes, revealing size-dependent behaviors and stability differences between armchair and zigzag configurations.

Contribution

It introduces a model linking Young's modulus to intrinsic axial strain and explores buckling modes, advancing understanding of phosphorene nanotube mechanics.

Findings

Armchair PNTs remain stable at higher temperatures due to lower intrinsic strain.

Young's modulus depends on nanotube diameter and intrinsic strain.

Buckling mode transitions from column to shell with increasing diameter/length ratio.

Abstract

Using molecular dynamics (MD) simulations, we explore the structural stability and mechanical integrity of phosphorene nanotubes (PNTs), where the intrinsic strain in the tubular PNT structure plays an important role. It is proposed that the atomic structure of larger-diameter armchair PNTs (armPNTs) can remain stable at higher temperature, but the high intrinsic strain in the hoop direction renders zigzag PNTs (zigPNTs) less favorable. The mechanical properties of PNTs, including the Young's modulus and fracture strength, are sensitive to the diameter, showing a size dependence. A simple model is proposed to express the Young's modulus as a function of the intrinsic axial strain which in turns depends on the diameter of PNTs. In addition, the compressive buckling of armPNTs is length-dependent, whose instability modes transit from column buckling to shell buckling are observed as the ratio of diameter/length increases.