We have used high-resolution transmission electron microscopy to resolve the @0001# projected basal plane structure and chirality relationships in boron nitride nanotubes. Evidence for tube growth along both ^101̄0& and ^112̄0& is found. Our results suggest that the ^112̄0& ~armchair! tubes form first. Subsequent growth can take the form of a ^101̄0& ~zig-zag! tube or additional armchair tubes. In ...

A new type of quantum interference device based on a graphene nanoring in which all edges are of the same type is studied theoretically. The superposition of the electron wavefunction propagating from the source to the drain along the two arms of the nanoring gives rise to interesting interference effects. We show that a side-gate voltage applied across the ring allows for control of the interf...

The structures of ideal armchair (5,5) single-wall carbon nanotubes (SWCNTs) of different lengths (3.7, 8.8, and 16.0 Å for C(40)H(20), C(80)H(20), and C(140)H(20)) and with 1-10 hydroxyl groups at the end of the nanotube were fully optimized at the B3LYP/3-21G level, and in some cases at the B3LYP/6-31G level, and the energy associated with the attachment of the OH substituent was determined. ...

A method based on density functional theory calculations is proposed for the preparation of chiral controlled single walled carbon nanotubes (SWCNTs) by tailoring the edges of bilayered graphene nanoribbons (GNRs). We find that armchair edged bi-layered GNRs are highly stable and need to be compressed to overcome the energy barrier to form zigzag SWCNTs, while the zigzag edged bi-layered GNRs a...

Motivated by the recent successful formation of MoSi2N4 monolayer [Hong et al., Sci. 369, 670 (2020)], structural, electronic and magnetic properties nanoribbons (NRs) is investigated for first time . The band structure calculations showed spin-polarization in zigzag edges a non-magnetic semiconducting character armchair edges. For armchair-edges, we identify an indirect to direct gap shift com...

we study the coherent spin-polarized transport through a zigzag-edge graphene flake (zgf), using hubbard model in the nearest neighbor approximation within the framework of the green function’s technique and landauer formalism. the system considered consists of electrode/ (zgf)/electrode, in which the electrodes are chosen to be armchair nanoribbons. the study was performed for two types of ele...