D. Ugarte, "Curling and closure of graphitic networks under electron-beam irradiation," Nature, 359:707-9, 1992.
Daniel Ugarte (Laboratörio Nacional de Luz Síncrotron, Campinas, Brazil): "This work was performed at the Institut de Physique Experimentale and the Institut Interdepartamental de Microscopie of the Ecole Polytechnique Fedrale de Lausanne in Switzerland.
"Carbon is a very peculiar element and presents a wide variety of chemical configurations. Although it is probably the most studied chemical element, revolutionary, pure carbon molecules and nanostructures (fullerenes, nanotubes, and so forth) were discovered only a few years ago (H. Kroto et al., Nature, 318:162-3, 1985; S. Iijima, Nature, 354:56- 8, 1991).
"Inspired by these recent developments, we decided to explore the response of carbon materials to the extreme conditions generated by an intense irradiation with high- energy electrons (300 keV). We observed that under the effect of the electron bombardment, nanometric carbon particles transformed spontaneously into a concentric arrangement ...
