CVD is also used to produced crystalline diamond in the form of films but require high substrate temperature and carbide forming substrates.
Nanodiamonds/diamond nanoparticles are formed by fully sp 3/tetrahedral hybridization, with a diameter of 700 ☌ to introduce vacancy in a post-growth process. This work brings new possibility for bottom-up nanomaterials synthesis based on nano and ultrafast laser physics. The energy dependence and the roles of the nonlinear phenomenon to the formation of homogeneous nanodiamonds are discussed. Nucleation of the carbon species in the confined plasma within the laser filaments leads to the formation of nanodiamonds. At laser energy higher than 300 μJ, emission spectra of C, O and H in the plasma were detected, indicating the dissociation of C 2H 5OH. The absorption of laser energy by ethanol increased non-linearly above 100 μJ accompanied by a white light continuum arises from fs laser filamentation. Here we show that nanodiamonds with the size of <5 nm are formed directly from ethanol via 1025 nm femtosecond laser irradiation. Nanodiamonds first discovered in meteorites are found to be biocompatible, non-toxic and have distinct optical properties. Carbon nanomaterials exhibit novel characteristics including enhanced thermal, electrical, mechanical and biological properties.
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