The Mobility of Carbon Atoms in Graphitic Nanoparticles Studied by the Relaxation of Strain in Carbon Onions

In-situ electron irradiation studies of metal-carbon nanostructures

The properties and the behaviour of nanoparticles are subjects of highest current importance. Experiments on individual clusters are generally difficult but can be carried out by the techniques of modern in-situ electron microscopy. The electron beam can be used as a tool to induce structural changes on an almost atomic scale [1].

One- and Two-Dimensional Diffusion of Metal Atoms in Graphene

In the present work, individual Au or Pt atoms in layersconsisting of one or twographene planes have been monitoredin real time at high temperature by high-resolution TEM. Weobtain information about the location of metal atoms ingrapheneandthediffusionmechanisms.Activationenergiesfordiffusion are obtained in a temperature range close to thetemperature of the technically important metal-assisted CVDprocess.Thematerialwassynthesizedinanarcdischarge

The diffusion of carbon atoms inside carbon nanotubes

We combine electron irradiation experiments in a transmission electron microscope with kinetic Monte Carlo simulations to determine the mobility of interstitial carbon atoms in single-walled carbon nanotubes. We measure the irradiation dose necessary to cut nanotubes repeatedly with a focused electron beam as a function of the separation between the cuts and at different temperatures. As the cutting speed is related to the migration of displaced carbon atoms trapped inside the tube and to their recombination with vacancies, we obtain information about the mobility of the trapped atoms and estimate their migration barrier to be about 0.25 eV. This is an experimental confirmation of the remar…