Oriented-attachment growth of diamond single crystal from detonation nanodiamonds

Possibility of growth of diamond single crystals from nanodiamond particles by oriented attachment mechanism under influence of organic substances has been suggested and experimentally confirmed. It has been found that diamond single crystals ranging up to 1.5μm are formed from the 4–5nm nanodiamond particles at high pressures and high temperatures treatment (HPHT; P~7GPa, T~1300°C). It has been experimentally shown that the necessary condition for the formation of the diamond single crystals is an addition of substances containing CH groups into HPHT chamber. The formation of the diamond single crystals has been confirmed by several experimental methods, including Raman scattering, scanning electron microscopy (SEM) and electron energy loss spectroscopy (EELS). Analysis of experimental results has shown that mechanism of oriented-attachment growth is responsible for formation of diamond single crystals. A model explained details of the mechanism has been suggested. [Display omitted] •Growth of diamond single crystal from nanoparticles of detonation nanodiamond due to oriented attachment mechanism has been observed for the first time.•Simplified scheme of oriented attachment growth of diamond single crystal from detonation nanodiamonds.•Faceted nanodiamonds assemble into microsized faceted single crystal.•SEM image of faceted diamond single crystals obtained by HPHT treatment of nanodiamonds.