Double-walled carbon nanocones: stability and electronic structure

We have applied first-principles calculations, based on the density functional theory, to investigate the stability and electronic properties of double-walled carbon nanocones, 60 degrees 60 degrees, 120 degrees 120 degrees and 60 degrees 120 degrees with different rotation angles between the walls. We have shown that the most favorable double-walled nanocone studied here is that of angles of 60 degrees 60 degrees, with rotation angle of 36 degrees and distance between apexes of 4.22 angstrom. We have found that, the interaction between the walls of rotated double-walled nanocones introduce geometric distortion in gap states, such as in Fermi level. These results should have consequences on the field emission properties of double-walled carbon nanocones. Additionally, we also investigated the spin polarization of such structures, and we have found unpaired electrons, which induces a total spin from 1 and 1/2 for 60 degrees 60 degrees and 60 degrees 120 degrees double cones, respectively.