Abstract
Density-functional theory (DFT) is employed to study the induced magnetization in nitrogen-doped arm-chair carbon nanotubes (ACNT:N) and assess the effect of application of electric field. Three fashions of dopants’ distributions were considered: (i) N-dopant atoms in a sequence of a chain along the ACNT; (ii) N-dopant atoms in alternating position with carbon atoms in a chain along the ACNT; and (iii) N-dopant atoms randomly distributed on the surface of ACNT. The results show that: (a) In absence of electric field, pristine and randomly N-doped ACNTs are paramagnetic. (b) Ferromagnetism/anti-ferromagnetism can be achieved when N-dopant atoms are close like in (sequenced or alternating) chain with number of N-dopant atoms odd/even, respectively. (c) Critical transversal electric field Fc ≅ 2 V/Å is needed for bandgap ionization of zigzag CNT (ZCNT) and found to be in excellent agreement with the experimental data. (d) Stronger transversal electric fields, F ≥ 4 V/Å, would be able to induce magnetization in ACNT:N. Assuming z-direction to be along the ACNT axle, then N-atom’s Pz orbital would contribute to σ-bonding whose energies are far deeper away from Fermi energy; so Mz = 0, and M→ = Mxi^ + Myj^ would always be radical to ACNT:N. The strong transversal field has the ability to tune the contributions of the π-bond electrons into building up the magnetization causing ferromagnetism and anti-ferromagnetism. Our results are benchmarked to the experimental data and theoretical results available in the literature. The relevance of our work to spintronic and gas-sensing devices is further discussed. Graphical abstract: [Figure not available: see fulltext.]
Original language | English |
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Pages (from-to) | 9277-9298 |
Number of pages | 22 |
Journal | Journal of Materials Science |
Volume | 57 |
Issue number | 20 |
DOIs | |
Publication status | Published - May 2022 |
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Science (miscellaneous)
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics