Eur. Phys. J. B (2015) 88: 236
https://doi.org/10.1140/epjb/e2015-60493-6

Regular Article

Structure, energetic stability and tunable electronic properties of B_xC_yN_z armchair nanotubes: a theoretical study on the influence of diameter and local carbon concentration

¹ Instituto de Física, Universidade Federal da Bahia, Campus Universitário da Federação, 40170-115 Salvador, BA, Brazil
² Departamento de Física, CCEN, Universidade Federal da Paraíba, Caixa Postal 5008, João Pessoa, PB, Brazil
³ Instituto Nacional de Ciência e Tecnologia em Energia e Ambiente – INCT&EA, Campus Universitário da Federação, Universidade Federal da Bahia, 40170-280 Salvador, Bahia, Brazil

^a e-mail: jemimafis@gmail.com

Received: 22 June 2015
Received in final form: 6 July 2015
Published online: 21 September 2015

Abstract

In this work we use density functional theory to perform a systematic theoretical study on the energetic stability, structure and electronic properties of armchair B_xC_yN_z nanotubes consisting of C and BN phases segregated in opposite diametrically ribbons focusing the calculations on the influence of the tube diameter and local carbon concentration on such properties. Interestingly, we have found that these nanotubes stabilize in a form presenting an ellipsoidal profile for the cross section, in contrast to the usual circular shape. For each investigated diameter, we closely follow how the band gap evolves during the transformation of BN into a C tube as the atomic stripes are being replaced. In fact, we have found that nanotubes with the same minimum width of C region present the same band gap despite their different diameters. In particular we have found a variety of systems that have tunable band gaps ranging from 0.27 eV up to 1.72 eV which could become of interest for specific applications.