Using density-functional theory the stability of armchair and zigzag single-walled carbon nanotubes and graphene nanoribbons was investigated. We found that the stability of armchair and zigzag nanotubes has different linear dependence with regard to their length, with switches in the most stable chirality occurring at specific lengths for each nanotube series. We explain these dependencies by ...

First-principles investigations on the edge energies and edge stresses of single-layer hexagonal boron-nitride (BN) are presented. The armchair edges of BN nanoribbons (BNNRs) are more stable in energy than zigzag ones. Armchair BNNRs are under compressive edge stress while zigzag BNNRs are under tensile edge stress. The intrinsic spin-polarization and edge saturation play important roles in mo...

The effect of defect complexes on the stability, structural and electronic properties of single-walled carbon nanotubes and boron nitride nanotubes is investigated using the ab initio pseudopotential density functional method implemented in the Castep code. We found more substantial atomic relaxations in the zig-zag carbon nanotube than the armchair one. We find that the B(C)B(c) defect introdu...

We investigate spin effects in transport across fully interacting, finite size graphene armchair nanoribbons (ACNs) contacted to collinearly spin-polarized leads. In such systems, the presence of short ranged Coulomb interaction between bulk states and states localized at the ribbon ends leads to novel spin-dependent phenomena. Specifically, the total spin of the low energy many-body states is ...

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...

Qiang Lu and Rui Huang Department of Aerospace Engineering and Engineering Mechanics, University of Texas, Austin, Texas 78712, USA ABSTRACT Based on atomistic simulations, the nonlinear elastic properties of monolayer graphene nanoribbons under quasistatic uniaxial tension are predicted, emphasizing the effect of edge structures (armchair and zigzag, without and with hydrogen passivation). T...

The movement of experimental philosophy criticizes traditional philosophy’s armchair reliance on intuition. The critique is rarely spelled out precisely; rather, experimental philosophers simply point to the admittedly surprising results of intuition surveys, which are, roughly, that intuitions vary with factors presumed to be irrelevant to the subject matter in question. However, the question ...

1. Kylie’s Puzzle On summer afternoons in Canberra, the baking sun reflects off Lake Burley Griffin, and the water shimmers. Up behind the university, in the botanical gardens, a cascading stream of water helps to maintain the humidity of the rainforest gully. These are just a couple of Kylie’s thoughts on the subject of water, her water thoughts. Amongst Kylie’s many other thoughts that involv...

We report optical properties of the smallest single-walled carbon nanotubes (SWNTs) with a diameter of only 3 A. These ultrasmall SWNTs are fabricated in the elliptical nanochannels of an AlPO-11 (AEL) single crystal. Polarized and resonant Raman scattering unambiguously revealed that these 0.3 nm SWNTs are of (2,2) armchair symmetry. Interestingly, the (2,2) armchair tube has two metastable gr...