Computer simulation of nanomaterials

A single-walled carbon nanotubes (SWCNTs) are a hollow cylindrical structure of carbon atoms with a diameter that ranges from 1 to 10 nm and having a length longer than this diameter. The structure of single-walled carbon nanotubes is clearly described by a chiral vector. Depending on the structural parameters, single-walled carbon nanotubes can be either metallic or semiconducting.In the first part of this thesis, the electronic properties (Fermi energy level, electronic density of states, energy band gap) and physical properties (atomic coordination number, bond-angle, bond-length and radial distribution function) under various uniaxial strain values at elevated temperatures are investigated. During simulations, Order (N) Tight-Binding Molecular Dynamics technique in parallel environment which is improved and successfully applied to SWCNT simulations by G. Dereli was used. We studied (18,0), (19,0), (20,0) and (22,0) zigzag SWCNTs. Depending on the applied uniaxial strain, metal ? semiconductor and semiconductor ? metal transitions are observed.In the second part, the electronic properties of different sizes (18,0), (19,0), (20,0) and (22,0) zigzag SWCNTs at 300K are investigated. In this study, nanoribbon, 8, 20, and 80 layered structures were chosen.In the third part of the thesis, the electronic and physical properties of (18,0), (19,0), (20,0) and (22,0) zigzag SWCNTs at low and high temperature are investigated.In the last part of the thesis, durability of (18,0), (19,0), (20,0) and (22,0) zigzag SWCNTs are investigated. Deformations due to uniaxial strain and heating are studied.Order (N), paralel tight-binding molecular dynamics program which is improved and written by Prof. Dr. Gülay Dereli is used in SWCNT simulations.