Geometrical structure, nuclear magnetic resonance (N1,1It) chemical shielding tensors, and chemical shiftsof silicon and carbon nucler are investigated for twn infinite size zigzag and armchair single-walled siliconcarbide nanotabes (SiCNTs). Geometrical structures of SieNTs, Sit bonds and bond angles of St and Cvertices in both zigzag and armchair nanotubes, Indicate that bond lengths are appr...

Light membranes composed of single-walled carbon nanotubes (SWNTs) can serve as efficient nanoscale vessels for encapsulation of tetrafluoromethane at 300 K and operating external pressure of 1 bar. We use grand canonical Monte Carlo simulation for modeling of CF4 encapsulation at 300 K and pressures up to 2 bar. We find that the amount of adsorbed CF4 strongly depends on the pore size in nanot...

We present an extensive first-principles study of the phonons in boron nitride nanotubes using density functional perturbation theory in the local density approximation. Based on the nonsymmorphic rod-group symmetry of the tubes, the Ramanand infrared-active modes at the G point of the one-dimensional Brillouin zone are evaluated. For zigzag and chiral nanotubes, the set of infrared-active mode...

Magnesium oxide nanotubes of finite length are investigated by the Density Functional Theory (DFT) at the B3LYP/6-31G (d) level. The (6, 0) zigzag and (4, 4) armchair of MgO nanotubes were considered and nuclear magnetic resonance properties including isotropic and anisotropic chemical shielding parameters (CSI and CSA) were calculated for 25Mg and 17O atoms of the optimiz...

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...

We consider the effects of Coulomb interactions on single-wall carbon nanotubes using an on-site Hubbard interaction, u . For the ~N ,N! armchair tubes the low-energy theory is shown to be identical to a two-chain Hubbard model at half-filling, with an effective interaction uN5u/N . Umklapp scattering leads to gaps in the spectrum of charge and spin excitations which are exponentially small for...

In this work, we study the interaction of extremely short pulses with a nonlinear anisotropic optical medium carbon nanotubes (armchair and zigzag type) metallic conductivity. The dependence pulse shape, width, intensity on nanotube chirality indices is analyzed. most appropriate type substantiated for providing localized propagation an electromagnetic field in properties. Keywords: anisotropy,...

We solve the Green's equation exactly for the armchair-type carbon nanotubes with the one-electron tight-binding Hamiltonian and obtain analytic expressions for the conductance of the nanotube with local perturbations. Our results explicitly show the dependence of the conductance on the Fermi level, the tubular radius, and the strength of the perturbation. A carbon nanotube is a new form of gra...