Nanometre-sized diamonds are more stable than graphite

Formation of nanodiamonds at near-ambient conditions via microplasma dissociation of ethanol vapour

“…The particles exhibit a uniform diameter of ca. 3.0 nm consistent with theoretical predictions 3,15 , and cubic diamond, lonsdaleite and the less frequently observed n-diamond phases similar to presolar nanodiamonds recovered from meteorites 16 . The formation of nanodiamonds at near-ambient conditions confirms their remarkable stability and could help realize new technologies such as drug delivery and the coating of polymeric substrates.…”

“…Atomistic models have predicted that at the nanoscale, hydrogen-terminated tetrahedral hydrocarbons, precursors to diamond phases, are thermodynamically more stable than polycylic aromatics, precursors to graphitic phases, with a transition in the phase stability occurring at B3 nm (ref. 3). This idea supports the existence of naturally formed diamond clusters, referred to as nanodiamonds, in petroleum 4 , interstellar dust 5 and candle flames, 6 all presumably formed at pressures and/or temperatures outside the stability field of bulk diamond.…”

Perspectives of Nanodiamond Formation From the Organic Matter at Low P-T Parameters

“…From the known data it's possible to conclude that we could provide the hydrothermal syntheses of nanodiamonds from the water-oil or water-alhocol-oil solutions, Nowdays for the commercial nanodiamond production detonation methods are used 1 .There are few other methods of the formation of nanodiamond particles at laboratory scale.Nanodiamond has been synthesized particularly by chlorination of carbide 2 , electron irradiation of carbon onions 3 and in the vapour phase in the substrate-free tube flow CVD reactor 4 .Meanwhile, Badziag et al 5 came to the conclusion that nanometer-sized diamonds could be more stable than graphite when formed from organic compounds -aromatic polycyclic hydrocarbons at low P-T parameters. These hydrocarbons were founded in the meteorite, interstellar diamonds 6 , in the kimberlitic diamonds and carbonados and in oil [7][8] …”

“…Meanwhile, Badziag et al 5 came to the conclusion that nanometer-sized diamonds could be more stable than graphite when formed from organic compounds -aromatic polycyclic hydrocarbons at low P-T parameters. These hydrocarbons were founded in the meteorite, interstellar diamonds 6 , in the kimberlitic diamonds and carbonados and in oil [7][8] …”

Metastable Nanosized Diamond Formation from Fluid Systems

“…Badziag et al 1 came to the conclusion that nanometer-sized diamonds could be more stable than graphite when formed from hydrocarbons with a H/C ratio of more than 0.24.…”