Formation of nickel-carbon heterofullerenes under electron irradiation

TL;DR

This paper proposes a method to produce nickel-carbon heterofullerenes via electron irradiation of graphene with nickel clusters, using molecular dynamics simulations to understand the transformation process and potential for experimental realization.

Contribution

It introduces a modified nickel-carbon potential for accurate simulation and reveals the atomic-scale transformation mechanism of heterofullerene formation under electron irradiation.

Findings

Heterofullerenes with nickel patches can form under electron irradiation.

The transformation process involves specific atomic rearrangements.

Estimated formation times align with experimental high-resolution electron microscopy conditions.

Abstract

A way to produce new metal-carbon nanoobjects by transformation of a graphene flake with an attached transition metal cluster under electron irradiation is proposed. The transformation process is investigated by molecular dynamics simulations by the example of a graphene flake with a nickel cluster. The parameters of the nickel-carbon potential (I. V. Lebedeva et al. J. Phys. Chem. C, 2012, 116, 6572) are modified to improve description of the balance between the fullerene elastic energy and graphene edge energies in this process. The metal-carbon nanoobjects formed are found to range from heterofullerenes with a metal patch to particles consisting of closed fullerene and metal clusters linked by chemical bonds. The atomic-scale transformation mechanism is revealed by the local structure analysis. The average time of formation of nanoobjects and their lifetime under electron irradiation are estimated for experimental conditions of high-resolution transmission electron microscope (HRTEM). The sequence of images of nanostructure evolution with time during its observation by HRTEM is also modelled. Furthermore, the possibility of batch production of studied metal-carbon nanoobjects and solids based on these nanoobjects is discussed.