Nanotubes are one of the most promising functional materials in nanotechnology. Silicon nanotubes (SiNTs) have been experimentally validated; they are unique puckered nanotubular structures unlike carbon nanotubes (CNTs). Although the electronic and optical properties of SiNTs have been previously studied, their structure-related capability for electron transport has not been investigated. Here...

Carbon nanotubes, which consist of only carbon atoms, were first discovered by Iijima [1] and can be thought of as a single layer of graphite that is wrapped into a cylinder. The cylindrical nanotubes are very stable and are regarded as the strongest fibers ever; nanotubes are extremely rigid to distortions along the tube axis whereas they are very flexible to those perpendicular to the axis [2...

We theoretically study the magnetoresistance of single wall carbon nanotubes (SWCNTs) in the ballistic transport regime, using a standard tight-binding approach. The main attention is directed to spin-polarized electrical transport in the presence of either axial or perpendicular magnetic field. The method takes into account both Zeeman splitting as well as size and chirality effects. These fac...

This paper discusses several important issues in a molecular dynamics simulation for analysing carbon nanotubes and their mechanical properties. In particular, the paper addresses the problems in selecting appropriate inter-atomic potentials, number of thermostat atoms, thermostat techniques, time and displacement steps and number of relaxation steps to reach the dynamic equilibrium. Based on t...

Spin polarized density functional theory has been used to investigate the structural stability and electronic properties of extrinsic and intrinsic defects in boron nitride nanotubes. Carbon substitutional defects under nitrogen rich and boron-rich growth conditions have the lowest heats of formation compared to boron and nitrogen antisites. Creating a defect reduces the band gap of the nanotub...

topological indices are one of the oldest and most widely used descriptors in quantitative structureproperties relationvhips (qspr). amongst the topological indices used a,s descriptors in qspic., the wienerindex is by far the most popular index. as it has been shown that the wiener index has a strong correlationwith the chemical propenies of the compound.in this study, the relationship between...

in this study, we have investigated radius dependence of hydrogen storage within armchair (n,n) single walled carbon nanotubes (swcnt) in a square arrays. to this aim, we have employed equilibrium molecular dynamics (md) simulation. our simulations results reveal that radius of carbon nanotubes are an important and influent factor in hydrogen distribution inside carbon nanotubes and consequentl...

The extinction and orientational dependence of electron diffraction from single-walled carbon nanotubes have been observed experimentally and investigated in detail theoretically using both algebraic analysis and numerical simulations. Electron diffraction from only achiral carbon nanotubes of zigzag or armchair structure shows observable orientational dependence and extinction of certain layer...

Rights: © 2011 American Physical Society (APS). This is the accepted version of the following article: Hashemi, M. J. & Sääskilahti, K. & Puska, Martti J. 2011. Local semiconducting transition in armchair carbon nanotubes: The effect of periodic bi-site perturbation on electronic and transport properties of carbon nanotubes. Physical Review B. Volume 83, Issue 11. 115411/1-5. ISSN 1550-235X (el...

Disorder effects on the density of states in carbon nanotubes are analyzed by a tight binding model with Gaussian bond or site disorder. Metallic armchair and semiconducting zigzag nanotubes are investigated. In the strong disorder limit, the conduction and valence band states merge, and a finite density of states appears at the Fermi energy in both of metallic and semiconducting carbon nanotub...