title: Atomic nanotube welders: boron interstitials triggering connections in double-walled carbon nanotubes.
abstract: Here we demonstrate that the incorporation of boron (B) atoms between double-walled carbon nanotubes (DWNTs) during thermal annealing (1400-1600 degrees C) results in covalent nanotube "Y" junctions, DWNT coalescence, and the formation of flattened multiwalled carbon nanotubes (MWNTs). These processes occur via the merging of adjacent tubes, which is triggered by B interstitial atoms. We observe that B atom interstitials between DWNTs are responsible for the rapid establishment of covalent connections between neighboring tubes (polymerization), thereby resulting in the fast annealing of the carbon cylinders with B atoms embedded in the newly created carbon nanotube network. Once B is in the lattice, tube faceting (polygonization) starts to occur, and the electronic properties are expected to change dramatically. Therefore, B atoms indeed act as atomic nanotube fusers (or welders), and this process could now be used in assembling novel electronic nanotube devices, nanotube networks, carbon nanofoams and heterojunctions exhibiting p-type electronic properties.
authors.affiliation: Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano-shi 380-8553, Japan. endo@endomoribu.shinshu-u.ac.jp
authors.forename: Morinobu
authors.initials: M
authors.lastname: Endo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Muramatsu
authors.forename: Takuya
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yoong-Ahm
authors.initials: YA
authors.lastname: Kim
authors.forename: Gregory
authors.initials: G
authors.lastname: Van Lier
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Charlier
authors.forename: Humberto
authors.initials: H
authors.lastname: Terrones
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.forename: Mildred S
authors.initials: MS
authors.lastname: Dresselhaus
mesh_terms: D001895:Boron / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D004583:Electrons; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011487:Protein Conformation; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D002244:Carbon; D001895:Boron