Materials Chemistry and Physics 239 (2020) 122107 Available online 31 August 2019 0254-0584/© 2019 Elsevier B.V. All rights reserved. Effect of point defects and low-density carbon-doped on mechanical properties of BNNTs: A molecular dynamics study A.R. Albooyeh a, * , A. Dadrasi b , A. Hamed Mashhadzadeh c a School of Engineering, Damghan University, Damghan, Iran b Department of Mechanical Engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran c Department of Mechanical Engineering, Azadshahr Branch, Islamic Azad University, Azadshahr, Iran HIGHLIGHTS � MD simulation was employed to investigate mechanical properties of zigzag and armchair BN nanotubes. � Mechanical properties of defective BNNTs with different numbers of missed atoms were considered. � The effect of doping different numbers of carbon atoms onto the BNNTs was evaluated. � The mechanical properties of both defective and doped BNNT showed reduction in every mentioned chirality. A R T I C L E INFO Keywords: BNNTs Carbon doping Defect Mechanical properties ABSTRACT By the employment of molecular dynamic simulations (MD), we investigated the mechanical properties of defective single-walled Boron nitride nanotubes (SWBNNTs) with zigzag and armchair chirality’s. After removing different numbers of atoms from nanotubes’ surface and putting samples under uniaxial tensile loading at constant strain rate Young’s modulus, failure stress and failure strain were calculated and the results demonstrated that the young’s modulus of armchair structures was higher than those of zigzag structure in every type of vacancy defect. However, failure strain and stress of zigzag structure were higher than armchair except in three atom vacancy defect type 2 in which one B and two N atoms were deleted from the surface. Furthermore, we considered the mechanical behavior of BNNTs with different numbers of doped carbon atoms. We found that Young’s modulus did not have a constant trend via rising in the number of carbon. The armchair structure showed higher or equal moduli compared to zigzag one except in one carbon-doped BNNTs. The maximum modulus of doped structures was observed in confguration antheacene for both chirality’s. Failure properties of zigzag doped BNNTs with 2, 4 and 6 carbon atoms and also 3 carbon rings doping were higher than those of armchair structure while in other doped BNNTs (2,4 and 5 carbon rings) reverse results were collected. 1. Introduction A class of nanomaterials like nanowires, nanosheets, and nanotubes have been under more attention of researchers over the past decades especially concerning their mechanical, thermal and electronic behavior. Tubular nanostructures including carbon and non-carbon nanotubes have recently been the subject of numerous studies because of showing noticeable properties [1–5]. Carbon nanotubes (CNTs), as the most famous tubular arrangement, have extensively been applied in many industrial applications like supercapacitors and actuators, semi- conductors, Lithium-Ion batteries, nano optoelectronic systems and nanocomposites due to its superior properties [6–8]. Nitride based nanotubes of group III periodic table such as Boron-nitride, Alumi- num-nitride, and Gallium-nitride are another class of nanotubes and BNNTs show remarkable characteristics in comparison to those of CNTs among them. This structure which was predicted by Rubio in 1994 [9] and frstly synthesized by Chopra in 1995 [10], exhibits higher thermal conductivity [11], mechanical strength [12] and hydrogen storage capability [13,14] compared to CNTs. It is also always semiconductor (wide bandgap of around 3.5–5.5 eV) irrespective of the tube’s radius or chirality while, CNTs could be either metallic or semiconductor depending on mentioned variables [15–17]. Although many * Corresponding author. E-mail address: a.albooyeh@du.ac.ir (A.R. Albooyeh). Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys https://doi.org/10.1016/j.matchemphys.2019.122107 Received 6 July 2019; Received in revised form 27 August 2019; Accepted 30 August 2019