The structure, energetics and thermal evolution of SiGe nanotubes

Abstract

The structure, energetics and thermal behavior of all the SiGe nanotubes in armchair and zigzag structures(n = 4–10) and two atomic arrangement types are investigated using the ab initio method andclassical molecular dynamics simulations. Gearlike and puckering configurations of SiGenanotubes are obtained. The simulation results indicate that large-diameter nanotubes aremore stable than small-diameter ones. Moreover, the type 1 (alternating atom arrangementtype) zigzag nanotubes are always more energetically favorable than the type 2 (layeredatom arrangement type) zigzag nanotubes. During the melting process, the melting-likestructural transformations from the initial nanotube to the compact nanowiretake place first, and then the compact nanowires are changed into agglomeratestructures at higher temperature. It is also found that the melting-like temperatures ofGe-substituted silicon nanotubes decrease with increase of the Ge concentration.