Ab initio study of ferromagnetic single-wall nickel nanotubes

Abstract

We performed ab initio spin-density functional theory calculations of the magnetic and electronic properties of ferromagnetic single-wall nickel nanotubes with various chiralities. A (6, 3) nanotube was found to have an energetically favorable “magic” structure and consequently it is expected to be observed experimentally for both free-standing and tip-suspended conditions, whereas a (5, 3) nanotube is expected to be observed only in the free-standing case. The (6, 3) and (5, 3) nanotubes, respectively, exhibit enhanced magnetic moments of 0.864 μB and 0.774 μB relative to 0.635 μB in Ni bulk, because of their low coordination numbers. The dependence of the magnetic moment on the chirality is predominated by the minority-spin dxy and dzx states in which the out-of-plane d orbitals interact strongly with each other due to the nanotube curvature.