Bao Wenxing,Zhu Changchun,Cui Wanzhao
(School of Electronics and Information Engineering,Xi'an Jiaotong University, Xi'an 710049, China)
Abstract:Focusing on the problem that the inter-atomic long-range nonbond interaction of carbon nanotubes cannot be represented by the empirical bond order potentials, a novel potential energy expression was presented£¬ combining the reactive empirical bond order potential with Lennard-Jones potential. It can represent the inter-atomic short-range interaction and long-range interaction of carbon, respectively£®It also can calculate the inter-atomic interaction potential energies of carbon nanotubes more accurately and more suitable for calculating carbon materials.Based on the extended bond potentials£¬molecular dynamic simulations are used to study the interaction potential energy of single-walled carbon nanotubes (SWCNTs) and Young's modulus£®The results show that the potential energy per atom decreases as the tubular diameters increase£®For pairs of tubes£¬the curve of interaction potential energy against distance shows a U alphabetic shape£® The Young's moduli of SWCNTs are about 0.935 TPa£®The simulation results accord with existing experiment values and other theoretical values perfectly£¬which demonstrates that the potential expressions can model the mechanical properties of carbon nanotubes exactly£®
Keywords:carbon nanotube; reactive empirical bond order potential; Lennard-Jones potential; molec-ular dynamics