Atomistic studies on tensile mechanics of bn nanotubes in the presence of defects

Boron nitride nanotubes (BNNTs) are of immense importance due to their many interesting functional features, notably biocompatibility and piezoelectricity and dominant mechanical strength as compared to carbon nanotubes (CNTs). The reliable implementation of these structures in an application is inherently related to its mechanical characteristics under external loads. The presence of defects in these structures severely affects the tensile properties. The effect of presence of point, line and Stone-Wales (SW) defects on the tensile behavior of BNNTs is systematically investigated by applying reactive force fields in molecular dynamics (MD) framework. Reactive force fields effectively describe the bond breaking and bond forming mechanism for BNNTs that are important for a practical situation. The Young's modulus of single-walled (10,0) BNNTs of length 100 nm has been found to be nearly 1.098 TPa, in good agreement with the available reports. The presence of defects has been shown to significantly reduce the tensile strength of the tube, while the number and separation of the defects effectively contribute to the percentage reduction. In addition, the effect of tube diameter and also the initial temperature are observed to strongly influence the tensile characteristics of BNNTs, indicating increased auxetic behavior than CNTs.