Investigation of Possible Structures of Silicon Nanotubes via Density-Functional Tight-Binding Molecular Dynamics Simulations and ab Initio Calculations

Abstract

We show, computationally, that single-walled silicon nanotubes (SiNTs) can adopt a number of distorted tubular structures, representing respective local energy minima, depending on the theory used and the initial models adopted. In particular, "gearlike" structures containing alternating sp(3)-like and sp(2)-like silicon local configurations have been found to be the dominant structural form for SiNTs via density-functional tight-binding molecular dynamics simulations (followed by geometrical optimization using Hartree-Fock or density function theory) at moderate temperatures (below 100 K). The gearlike structures of SiNTs deviate considerably from, and are energetically more stable than, the smooth-walled tubes (the silicon analogues of single-walled carbon nanotubes). They are, however, energetically less favorable than the "string-bean-like" SiNT structures previously derived from semiempirical molecular orbital calculations. The energetics and the structures of gearlike SiNTs are shown to depend primarily on the diameter of the tube, irrespective of the type (zigzag, armchair, or chiral). In contrast, the energy gap is very sensitive to both the diameter and the type of the nanotube.

Chemistry of one dimensional silicon carbide materials: Principle, production, application and future prospects

“…The M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 10 calculated high formation energies of the single wall CNT like single wall SiNTs [88] or the rolled-up Si (111) sheets [89] in comparison to the bulk silicon with diamond structure confirms the above argument. Several theoretical investigations have suggested the possibility of formation of silicon nanotubes based on rolled-up graphene-like sheets and predicted their structures and properties but experimental results are contrary to that [88][89][90]. Fagan et al [91] have applied the DFT and showed the similarities in the electronic and structural properties of SiNTs and CNTs.…”

An Ab Initio Study of Atomic Hydrogen and Oxygen Adsorptions on Armchair Silicon Nanotubes

“…Radial buckling is also calculated for the armchair Si nanotubes. Small nanotubes (Si(4 4) and Si (5 5)) have high buckling with a puckered gear-like structure 47 (the gear-like structure is that of a deformed tubular shape) and nanotubes through Si(6 6) to Si (12 12) have very small buckling with a smooth CNTlike tube (Fig. 1).…”

Thermal transport in silicene nanotubes: Effects of length, grain boundary and strain

“…Epur et al reported a new and straightforward approach including magnesium oxide nanorods for generating the hollow silicon nanotubes [30]. Also, intensive theoretical studies based on density functional theory and molecular dynamics simulation have been conducted to investigate the possibility of the existence of silicene nanotubes [31,32] as well as the stability and geometric structure of single and double-walled silicone nanotubes [33]. Wang et al studied the stability and electronic features of silicone nanotubes.…”