title: Divacancies in graphene and carbon nanotubes.
abstract: Divacancies are among the most important defects that alter the charge transport properties of single-walled carbon nanotubes (SWNT), and we here study, using ab initio calculations, their properties. Two structures were investigated, one that has two pentagons side by side with an octagon (585) and another composed of three pentagons and three heptagons (555777). We investigate their stability as a function of tube diameter, and calculate their charge transport properties. The 585 defect is less stable in graphene due to two broken bonds in the pentagons. We estimate that the 555777 becomes more stable than the 585 for a diameter of about 40 A (53 A) for an armchair (zigzag) SWNTs, indicating that they will prevail in large diameter multiwalled carbon nanotubes and graphene ribbons.
authors.affiliation: Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970, São Paulo, SP, Brazil.
authors.forename: Rodrigo G
authors.initials: RG
authors.lastname: Amorim
authors.forename: A
authors.initials: A
authors.lastname: Fazzio
authors.forename: Alex
authors.initials: A
authors.lastname: Antonelli
authors.forename: Frederico D
authors.initials: FD
authors.lastname: Novaes
authors.forename: Antônio J R
authors.initials: AJ
authors.lastname: da Silva
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D004553:Electric Conductivity; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D002244:Carbon