Antisites, C substitutionals and vacancy defects in nanotubes were investigated by means of first-principles total energy calculations which were based upon a density functional spin-polarized method. All of the defects introduced localized energy levels into the band-gap. For some open-shell systems (C substitutionals and vacancy defects), the levels in the gap region presented an exchange splitting that was greater than 0.5eV. The CB and NB defects, under N-rich growth condition, and CN under B-rich growth condition, presented the lower formation energies.

Theoretical Study of Native Defects in BN Nanotubes. T.M.Schmidt, R.J.Baierle, P.Piquini, A.Fazzio: Physical Review B, 2003, 67[11], 113407 (4pp)