title: Catalytic action of gold and copper crystals in the growth of carbon nanotubes.
abstract: Multi-wall carbon nanotubes are grown in a chemical vapor deposition process by using bulk gold and copper substrates as catalysts. Nanotube growth starts from a nanometer-sized roughness on the metal surfaces and occurs in a mechanism where the catalyst particle is either at the tip (Au) or root (Cu) of the growing nanotube. Whereas Au leads to nanotubes with good structural perfection, nanotubes grown from Cu show a higher density of defects. High-resolution transmission electron microscopy shows the bonding between Au and carbon at the metal-nanotube interface whereas no bonds between Cu and carbon occur. Highly mobile Au or Cu atoms adsorb at the growing edge of a carbon nanotube from where diffusion along the nanotube wall can lead to the formation of Au or Cu nanowires inside the central hollow of carbon nanotubes.
authors.affiliation: Institut de Physique et Chimie des Matériaux, UMR 7504, CNRS, Université de Strasbourg, 23 rue du Loess, 67034 Strasbourg, France.
authors.forename: Pawan K
authors.initials: PK
authors.lastname: Tyagi
authors.forename: Izabela
authors.initials: I
authors.lastname: Janowska
authors.forename: Ovidu
authors.initials: O
authors.lastname: Cretu
authors.forename: Cuong
authors.initials: C
authors.lastname: Pham-Huu
authors.forename: Florian
authors.initials: F
authors.lastname: Banhart
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D037742:Nanotubes, Carbon; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D006046:Gold; D003300:Copper