Buckling of blue phosphorus nanotubes under axial compression: Insights from molecular dynamics simulations

We report on mechanical properties of blue phosphorus nanotubes (BluePNTs) from systematic molecular dynamics simulations, adopting a Stillinger-Weber potential with parameters determined by fitting to energetic and structural data from first-principles calculations. Our results corroborate the previously reported bending poison effect and size-dependent buckling behaviors. Under axial compression, current simulations predict a shell-to-column buckling mode transition for BluePNTs with increasing aspect ratios; further compression of BluePNTs with large aspect ratios results in a column-to-shell buckling mode transition. Associated critical buckling strains can be described by the continuum mechanics theory. We also simulated buckling behavior of black phosphorus nanotubes (BlackPNTs) and found that the buckling modes of BluePNTs exhibit much less chirality dependence compared to BlackPNTs, stemming from subtle structural differences between these two closely related yet distinct systems. The present results offer insights into key structural and mechanical properties of BluePNTs for fundamental understanding and potential applications of this relatively new member of the large and diverse nanotube family of materials.