Boron adsorption induced magnetism in zigzag boron nitride nanotubes

In this paper, we have studied the boron adsorption induced magnetism in zigzag boron nitride nanotubes (BNNTs) and BN hexagonal sheets (h-BN sheet) as well as the magnetic interaction between the B-induced magnetic moment by using the first principle spin-polarized density functional calculations. It is found that the adsorption of a single B adatom on the external surface of BNNTs and h-BN sheet can induce spontaneous magnetization in the B-BNNTs system with a local magnetic moment of 1.0 mu(B) per B adatom regardless of the tube diameter and the bonding between the B atom and the BNNTs/BN sheets. An analysis of orbital hybridization indicates that two valence electrons participate in the bonding and the remaining one electron of the B adatom are confined at the adsorption site and contribute to the magnetism accordingly. The magnetic interactions between the B-induced magnetic moments on BNNTs have been explored. The magnetic B-BNNTs may be experimentally accessible when the coverage of B-ad adatoms adsorbed on the external surface of BNNTs is low. (C) 2012 Elsevier B.V. All rights reserved.