Interaction of carbon clusters with Ni(100) : Application to the nucleation of carbon nanotubes

TL;DR

This study uses tight-binding Monte Carlo simulations to explore how different carbon structures interact with Ni(100) surfaces, shedding light on the early stages of carbon nanotube nucleation.

Contribution

It provides new insights into the stability and adhesion mechanisms of carbon structures on nickel surfaces during nanotube formation.

Findings

Dangling bonds in flat carbon sheets remain unsaturated.

Adhesion is driven by energy gain in surface Ni atoms.

Carbon caps are stabilized by occupation of hollow sites.

Abstract

In order to understand the first stages of the nucleation of carbon nanotubes in catalytic processes, we present a tight-binding Monte Carlo study of the stability and cohesive mechanisms of different carbon structures deposited on nickel (100) surfaces. Depending on the geometry, we obtain contrasted results. On the one hand, the analysis of the local energy distributions of flat carbon sheets, demonstrate that dangling bonds remain unsaturated in spite of the presence of the metallic catalyst. Their adhesion results from the energy gain of the surface Ni atoms located below the carbon nanostructure. On the other hand, carbon caps are stabilized by the presence of carbon atoms occupying the hollow sites of the fcc nickel structure suggesting the saturation of the dangling bonds.