Catalyst-free boron nitride (BN) and carbon (C) nanoflakes have been produced by direct radio frequency (RF)-magnetron sputtering on molybdenum and tungsten substrates at or above temperatures of 1000 °C and 800 °C, respectively. Selected-area electron diffraction (SAED) shows that the films are polycrystalline and contain disordered graphite and hexagonal BN. Transmission electron microscopy (TEM) reveals curved or twisted flakes up to several hundred nanometres in length. High resolution transmission electron microscopy (HRTEM) confirms the nanoflake structure to be turbostratic, which is intermediate between an amorphous phase and the ordered layered phases of hexagonal BN or graphite.
Zhu, D., Jakovidis, G., & Bourgeois, L. (2010). Catalyst-free synthesis of carbon and boron nitride nanoflakes using RF-magnetron sputtering. Materials Letters, 64(8), 918 - 920. https://doi.org/10.1016/j.matlet.2010.01.058