An investigation was made of the stability of boron nitride conical sheets of nm-size, using first-principles calculations. The results indicated that cones with an antiphase boundary (a line defect that contained either B-B or N-N bonds) could be more stable than those without one. It was also found that doping the antiphase boundaries with C could enhance their stability, also leading to the appearance of localized states in the band-gap. Among the structures which were considered, the one with the smallest formation energy was a cone with a C-modified antiphase boundary that presented a spin splitting of ~0.5eV at the Fermi level.

Stability of Antiphase Line Defects in Nanometer-Sized Boron Nitride Cones. S.Azevedo, M.S.C.Mazzoni, R.W.Nunes, H.Chacham: Physical Review B, 2004, 70[20], 205412 (6pp)