Mechanical, electronic and stability properties of multi-walled beryllium oxide nanotubes and nanopeapods: a density fun

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ORIGINAL PAPER

Mechanical, electronic and stability properties of multi-walled beryllium oxide nanotubes and nanopeapods: a density functional theory study Y. Rostamiyan 1 & V. Mohammadi 1 & Amin Hamed Mashhadzadeh 2 Received: 29 October 2019 / Accepted: 23 February 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract Single-, double-, and triple-walled beryllium oxide nanotubes (BeONTs) along with BeO nanopeapods were simulated and geometrically optimized under the density functional theory (DFT) framework to investigate their Young’s modulus, electronic properties, and stability. We found better properties in single-walled nanotubes, either their electronic or mechanical properties, than other mentioned nanotubes. Increase in the radius and inter-wall distance made an overall decrease in the Young’s modulus of SW and DW BeONTs. The highest obtained modulus of SWBeONTs and DWBeONTS was calculated for structures (14,0) and (8,0)@(14,0) with the magnitudes of 700.12 Gpa and 712.24 Gpa, respectively. In addition, increasing the wall number from one to two resulted to significant growth in Young’s modulus of DWBeONTs while created no significant difference between DWBeONTs and TWBeONTs. Bandgap energy of single-walled nanotubes was higher than those of double- and triple-walled nanotubes, and the bandgap showed consistent soar in both SW and DW BeONTs via increase in the radius and inter-wall distance, respectively. Furthermore, considering nanopeapods with various interlayer distances revealed that the Young’s modulus and energy gap behavior of these structures were similar to what we observed in SWBeONTs. However, nanopeapods showed weaker mechanical and semiconducting properties compared with SWBeONTs. Moreover, calculating the formation energies of all under consideration structures revealed a reduction of formation energy via an increase in the dimension of singlewalled nanotubes, an increase in the dimension of nanotubes via adding more walls, and an increase in the dimension of peapod structures as well, and the bigger structures are more stable than smaller ones. Keywords Beryllium oxide nanotube . DFT . Mechanical properties . Nanopeapods . DOS

Introduction Tubular structures including carbon and non-carbon nanotubes have extensively been considered by researchers since the introduction of carbon nanotubes (CNTs) to the world by Iijima [1]. With recent advancements of nanotechnology, these one-dimensional nanostructures have been used in different industries such as field emission sources, nanocomposites, super capacitors and actuators, lithium-ion batteries,

* Amin Hamed Mashhadzadeh [email protected]; [email protected] 1

Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran

2

Department of Mechanical Engineering, Azadshahr Branch, Islamic Azad University, Azadshahr, Iran

semiconductors, and nano-optoelectronic systems due to their superior properties [2–4]. Numerous experimental and theoretical works have been conducted to fi