Eur. Phys. J. B (2013) 86: 389
https://doi.org/10.1140/epjb/e2013-40739-1

Regular Article

Ab initio study of dielectric function of C-substituted single walled boron nanotubes

Nanomaterials Research Group, Computational Nanoscience and Technology Lab, ABV-Indian Institute of Information Technology & Management, 474015 Gwalior ( MP), India

^a e-mail: pankajs@iiitm.ac.in

Received: 4 July 2013
Received in final form: 6 August 2013
Published online: 18 September 2013

Abstract

We report dielectric function related optical properties namely dielectric constant, static dielectric constant, and absorption coefficients of C-substituted hexagonal boron nanotubes. The optical properties were computed for parallel and perpendicular polarized light in the framework of density functional theory. In this regard, three models of BNTs namely armchair (3,3), zigzag (5,0), and chiral (4,2) have been undertaken for probing the effect of carbon impurity. Our calculations show high dielectric constant of armchair and chiral BNTs for parallel polarized light and magnitude becomes smaller for higher impurity concentration, while zigzag BNT exhibits reverse trend for high impurity concentration. For perpendicular polarized light, the magnitude of dielectric constant ϵ₁(ω) is decreased and shifts at higher frequencies. The absorption is revealed highest for armchair followed by zigzag and chiral BNTs independent of impurity concentration. The intensity of absorption gets weaken for higher concentration. The chiral BNTs show smaller but uniform absorption in smaller frequency range results in uniform field emission. These findings are also compared with available experimental and theoretical results. These metallic nanotubes are promising candidate as interconnects for nanodevices as well as field emission devices.