Mechanical properties of silicon-germanium nanotubes: A molecular dynamics study

In current article, molecular dynamic simulation was selected to estimate the mechanical properties of silicon-germanium nanotubes (SiGeNTs) according to their chirality, dimension and temperature and the effect of vacancy and Stone-Wales defects on mechanical properties of single-walled SiGeNTs (SWSiGeNT) were also considered. The results demonstrated that Young's modulus of all single-walled zigzag structures was higher than that of armchairs with corresponding close radius while, armchair structures showed higher failure strain and failure stress in contrast. Young's modulus of both chirality's totally decreased with increase in radius while, failure strain and failure stress rose instead. The same results were observed in Double-wall SiGeNTs (DWSiGeNTs) and Three-wall SiGeNTs (TWSiGeNTs) where again, armchairs presented higher failure properties and lower Young's modulus. In general, Young's modulus grew steadily via growth in the number of nanotube's walls. In terms of defects influence it is obviously seen that, all types of defects decreased the mentioned properties and increase in the number of missed atoms made a higher reduction in the desired properties. Although the armchair configuration revealed higher failure properties than zigzag one in every vacancy or Stone-Wales defect, regarding to Young's modulus we found a reverse manner except in some three atom vacancies.