Ab initio model of carbon nanotubes growth on nano-structured Ni catalyst in a nanoporous Al2O3 membrane and resistance calculations for their junctions with various metal substrates

We consider the carbon nanotube growth in nanoporous alumina membranes comparing the results of ab initio simulations performed on 2D periodic models of C/Ni(111) and C/θ-Al2O3(010) nanostructures. Our results predict a quite effective and reproducible growth of carbon nanotubes upon the nickel nanostructured substrate. In absence of catalyst nanoparticles upon the bottom of the nanopores inside alumina membrane, the carbon structures could grow from the walls towards the centers of nanopores, yielding either carbon nanoscrolls or rather thick amorphous (soot-like) microtubes. We also consider the junctions of carbon nanotubes with contacting metallic elements of a nanocircuit, carrying out numerical simulations on the contacts resistance, using multiple scattering theory and the effective media cluster approach. Calculations for different multiwalled nanotube-metal contacts yield quantitatively realistic results, from several to hundreds kOhm, depending on nanotube chirality, diameter and thickness. As an indicator of possible 'radial current' losses we also report on the simulation of the multiwalled nanotube inter-wall transparency coefficient.