Coalescence of clusters of catalysts for the growth of carbon nanotubes during their formation under homogeneous and heterogeneous conditions

The formation of clusters of catalysts for the growth of carbon nanotubes has been investigated experimentally and theoretically. An expression for the size distribution of monomolecular and globular clusters formed upon coalescence has been obtained. It has been shown that the maximum of the distribution is determined by the effective surface tension coefficient. The effective surface tension coefficients for clusters formed in the gas phase and on the substrate have been estimated. It has been found that the effective surface tension coefficient for a substrate based on silicon oxide is less than that of the clusters formed on silicon and in the gas phase. In the case of a globular cluster, the effective surface tension coefficient tends to the characteristic value for the bulk material.