Energetics and electronic structure of armchair nanotubes with topological line defects

• Published in: Journal of physics. Condensed matter 2007-09, Vol.19 (36), p.365231-365231 (7)
• Main Authors: Okada, Susumu, Nakada, Kyoko, Kawai, Takazumi
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.)
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/36/365231

We study the electronic structure and energetics of carbon nanotubes with topological line defects consisting of fused pentagons and octagon rings by means of first-principles calculation in density functional theory and tight-binding molecular dynamics simulations. The tubes with the topological line defects are found to exhibit magnetic ordering where polarized electron spins are localized around the topological defect and ferromagnetically aligned along the defect. Our analyses of the electronic energy band and spin density distributions reveal that this ferromagnetic spin ordering is associated with the edge states that are inherent in the graphite ribbon with zigzag edges. The tight-binding molecular dynamics simulations show that the nanotubes with the topological line defects are thermally stable up to temperature of 3000 K and disrupted over 4000 K.