Nanocrystalline carbon flakes deposited by RF magnetron sputtering

•Carbon nanoflakes were grown by RF sputtering.•Ultra nanocrystalline graphitic was observed by TEM and confirmed by Raman spectra.•The temperature is a key parameter to obtain a polycrystalline structure.

Carbon nanostructures were prepared by RF magnetron sputtering at deposition times from 30 to 120 min and temperatures on silicon substrates from 390 °C to 510 °C. Scanning and transmission electron microscopy (TEM) observations showed that carbon films deposited at 510 °C consisted of nanostructured polycrystalline carbon nanoflakes. Dark field TEM images showed carbon nanocrystals of 1 nm average size. The sp2 hybridization decreases with increasing deposition time, as it was confirmed by X-ray photoelectron spectroscopy. The nature of these carbon nanostructures would be turbostratics, an intermediate state between hexagonal and amorphous phases.