Thermoatomic analysis of monovacancy defected single-walled boron nitride nanotube under quasi-static strain: Insights from molecular dynamics

Abstract

The structural and thermal stability of single-walled boron nitride nanotubes (SWBNNTs) under strained conditions are essential in pursuit of their applications that are subjected to high temperature processing and/or working environment. However, there are dearth of high temperature (>1000 K) studies on SWBNNTs and other forms of hexagonal boron nitride (h-BN) structures, either with or without defects, due to experimental difficulties. In this paper, an atomistic approach is adopted to perform uniaxial tensile and torsional quasi-static straining of pristine and monovacancy defected SWBNNTs at different temperatures while the thermal stability of monovacancy defected SWBNNT structures were predicted from its mean square displacement during equilibration up to 2400 K temperature. During uniaxial tensile and torsional straining, Young's modulus, Poisson's ratio, and shear modulus values of monovacancy defected SWBNNTs decreases on increasing the temperature condition compared to high temperature. For instance, in case of monovacancy concentration of 0.2% in SWBNNTs, the increase in temperature from 300 K to 2400 K reduced its Young's, Poisson's ratio, axial strain and shear moduli by 14%, 19%, 50.5%, and 87.28%, respectively. Findings of this work may have future implication in extreme temperature applications of BNNT-based structural materials.