Computational studies on aluminum nitride and aluminum phosphide nanotubes: density functional calculations of 27Al electric field gradient tensors

Abstract

Nuclear quadrupole resonance (NQR) parameters including the nuclear quadrupole coupling constant (C Q ) and asymmetry parameter (g Q ) at the sites of various 27 Al nuclei on (6,0) zigzag and (4,4) armchair AlN and AlP nanotubes (NTs) were calculated by using the density functional theory (DFT) method to study the properties of the electronic structures of the nanotubes. Geometry optimizations were carried out at the B3LYP/6-31G* level of theory using the Gaussian 03 suite of programs. The calculated electric field gradient tensors were converted to the nuclear quadrupole resonance parameters, C Q constant, and g Q parameter. The quadrupole resonance parameters in each of the structures were divided into four layers with equivalent electric field gradient tensor eigenvalues in each layer. The results show that, in AlN and AlP nanotubes, the Al atoms at the edges of the nanotubes play dominant roles in determining the electronic behavior of the nanotubes and important roles in growth and synthesis processes of the nanotubes. Also the average values of C Q ( 27 Al) for the AlNNT models were higher in comparison with the AlPNT models, while variations of C Q ( 27 Al) in AlPNTs were greater in comparison with in AlNNTs.

Quantum molecular descriptors and adsorption properties of SCN− on (6,0), (7,0), (8,0), and Ga-doped (6,0) zigzag single-walled boron nitride nanotubes: a computational study

“…Many studies have investigated non-carbonbased nanotubes which exhibit electronic properties independent of these parameters. Among such nanotubes, use of group III and V elements, which are neighbors of C in the periodic table, has been an interesting subject of many studies, using materials such as boron nitride (BN) [6], aluminum nitride (AlN) [7], gallium nitride (GaN) [8], indium nitride (InN) [9], boron phosphide (BP) [10], aluminum phosphide (AlP) [11], gallium phosphide (GaP) [12], and indium phosphide (InP) [13]. These nanotubes are inorganic analogs of carbon nanotubes (CNTs) and have good physical properties for a broad variety of applications; such nanotubes are always semiconductors [14].…”