Electron-Irradiation-Induced Ordering In Tetrahedral-Amorphous Carbon Films

Evolution kinetics of sp2 ordering in tetrahedral amorphous carbon films induced by electron irradiation

“…However, we should consider that the case (m = 1, d = 3, n = 0) is most plausible from the reasons that follow. Highly resolution TEM observations of the irradiated areas showed that electron irradiation generates ordered phases, which look like multiwalled nanotubes [20] or severely wrinkled graphite sheets. On the other hand, TEM observations did not reveal any signature of the presence of the nuclei that could grow two-dimensionally (d = 2) to such three-dimensional structures.…”

“…A previous study by the present authors [20] showed that ta-C films, when irradiated with a focused TEM electron beam with energy of 200 keV or 100 keV, exhibit transformation to nanotubelike ordered structures which is detected by the development of a new hallo ring in the electron diffraction and the graphene-originated p* peak in electron energy loss spectra (EELS). Our experiments indicated that the structural conversion from the ta-C structure to a graphitic phase could be interpreted neither by heating effects nor by ordinary displacement damage effects [20].…”

“…Our experiments indicated that the structural conversion from the ta-C structure to a graphitic phase could be interpreted neither by heating effects nor by ordinary displacement damage effects [20]. In this paper, we report results of an extended EELS study in which the progressive evolution of the sp 2 ordered structure in ta-C films was measured as a function of irradiation time.…”

Amorphous Carbon under 80 kV Electron Irradiation: A Means to Make or Break Graphene

“…[ 3 ] For example, the irradiation of amorphous carbon with a 100 or 200 keV electron beam has been shown to lead to the formation of sp 2 carbon onions. [ 4 ] The mechanism behind this catalyst-free electron beam induced graphitization is widely argued to arise from radiation-induced diffusion [ 5 ] which may qualitatively be thought of as similar to thermal diffusion. [ 3 ] However, it is usually argued that heating effects are simply too limited to play a signifi cant role.…”

In Situ Room Temperature Electron-Beam Driven Graphene Growth from Hydrocarbon Contamination in a Transmission Electron Microscope

“…It is well known that electron beam irradiation can graphitize amorphous carbon through radiolysis reactions (breaking bonds and allowing diffusion and rearrangement of C species) [ 36 , 37 ]. If freestanding amorphous carbon is irradiated, sp 2 carbon onions form (spherical graphene cages within each other) [ 38 , 39 ]. The process of forming a graphitic spherical structure is argued to occur so as to avoid dangling bonds and to distribute strain evenly and in this way seek energy minimization [ 38 ].…”