Coating geometries of metals on single-walled carbon nanotubes

摘要

This paper studies the coating geometries of metals on single-walled carbon nanotubes u0001SWNTsu0002 onnthe basis of the nucleation theory and wetting theory. The metal surface energy, cohesion energy,ndiffusion barrier, and metal-SWNT interfacial energy are calculated using first-principlesncalculation. Metals including Fe, Al, Au, Pd, Ni, and Ti are considered. For Ti, Ni, and Pd, lownmetal-SWNT interfacial energies and high diffusion barriers are responsible for forming continuousnor quasicontinuous layers on the SWNT surface. In contrast, Al and Au have small diffusion barriersnand poor SWNT surface wetting, thus they tend to aggregate and form large clusters. Although thenbinding energy between Fe and SWNTs is large, due to the large cohesion energy and poor wetting,nFe may form isolated clusters. All results are in good agreement with experimental observations.