Properties of 5d atoms doped boron nitride nanotubes: a first-principles calculation and molecular orbital analysis

The geometry, electronic structure and magnetic property of boron nitride nanotube (BNNT), whose boron/nitride atoms are substituted by 5d atoms (B-5d or N-5d), are investigated by first-principles calculations based on density functional theory. The pureBNNT and BNNT with boron vacancy (V-B) or nitrogen vacancy (V-N) are also investigated for comparison. Results show that the local symmetry of B-5d system is similar to C-3v, however the N-5d system exhibits a large geometric deviation from C-3v. The total magnetic moments of doped systems are different from each other, and B-5d system present a strong regularity. The total density of states is presented, where impurity energy levels exist. The impurity energy levels and total magnetic moment can be explained by the molecular orbital theory under C-3v symmetry.