title: Growth morphology and spectroscopy of multiwall carbon nanotubes synthesized by pyrolysis of iron phthalocyanine.
abstract: Carbon nanotubes (CNTs) were synthesized by Chemical Vapor Deposition (CVD) from the pyrolytic decomposition of Iron Phthalocyanine (FePc) molecules, on SiO2/Si(111) substrates in the presence of a hydrogen flow. FePc molecules contribute simultaneously both to the formation of the precursor Fe nanoparticles and also as a Carbon source. Different experimental conditions were examined. Samples were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and inverse photoemission. The resulting samples are highly oriented multiwall carbon nanotubes films, with heights in the range between: 4 and 20 microm. The tubes diameter is strongly dependent on growth temperature. Our experimental results show evidence of a transition in the growth mechanism, from a tip growth to a base growth mode, as the decomposition temperature is increased. Preliminary spectroscopic measurements performed on these MWCNTs, show the unoccupied density of states has several resonances close to Fermi level, related both to the graphene electronic structure and the formation of the tube.
authors.affiliation: Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Segura
authors.forename: Wladimir
authors.initials: W
authors.lastname: Ibáñez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Soto
authors.forename: Samuel
authors.initials: S
authors.lastname: Hevia
authors.forename: Patricio
authors.initials: P
authors.lastname: Häberle
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D003460:Crystallization / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry* / Q000528:radiation effects; D006358:Hot Temperature; D007211:Indoles / Q000737:chemistry* / Q000528:radiation effects; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D005296:Ferrous Compounds; D007211:Indoles; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; C493990:iron phthalocyanine