Stable geometries and magnetic properties of single-walled carbon nanotubes doped with3dtransition metals: A first-principles study

Abstract

The interaction of 3d transition metal atoms and dimers with a single-walled armchair carbon nanotube has been investigated by first-principles density functional calculations. For Fe-, Co-, and Ni-doped ͑4,4͒ nanotubes, outside adsorption sites are the most favorable. The interactions are largely ferromagnetic for Fe and Co, with the local magnetic moments of the dimers being similar to the free dimers. However, for Ni most structures are nonmagnetic. We have also examined the effects of curvature with calculations for graphene and the ͑8,8͒ nanotube. For the ͑8,8͒ nanotube, the interaction of Co becomes more favorable inside the nanotube. Doping of a single Co atom transforms the ͑4,4͒ and ͑8,8͒ nanotubes into half-metals. These results are useful for spintronics applications and could help in the development of magnetic nanostructures and metallic nanotube coatings.

Irradiation-Induced Magnetism in Graphite: A Density Functional Study

“…Thus, our results stress the importance of hydrogen for the development of the magnetic state [35] and offer a possible explanation for the results of experiments on graphite irradiation with H and He ions: hydrogen irradiation should result in a much stronger magnetic signal. It is worth noting that the large moment of H at a vacancy predicted here implies that H impurities are as important as Fe impurities for carbon systems [36]. Finite magnetic moments of naked vacancies also indicate that a weakly magnetic sample could be produced by irradiating with He ions, but at very low temperatures, when recombination of Frenkel pairs is suppressed.…”

Theory of Fano resonances in graphene: The influence of orbital and structural symmetries on STM spectra

“…This prediction of Co above the middle of a hexagon is in line with previous DFT calculations. 30,31 The following discussion will be based on the fully relaxed structure minimum-energy structure of Co above the middle of a hexagon as shown in Fig. 1.…”

Adsorption of transition-metal atoms on boron nitride nanotube: A density-functional study

“…The metal component can be a single atom, a metal cluster, or a planar metal surface. [2][3][4] Many previous studies have provided fundamental insights into potential applications of metal-adsorbed carbon nanotubes in various fields. The fact that the electronic properties of carbon nanotubes can be either metallic or semiconducting, depending on the tube diameter and helicity, 5 also renders metal-adsorbed carbon nanotubes a versatile tubular nanomaterials.…”