Oriented-attachment growth of diamond single crystal from detonation nanodiamonds

Abstract 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 1.5 μm are formed from the 4–5 nm nanodiamond particles at high pressures and high temperatures treatment (HPHT; P  ~ 7 GPa, 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 C H 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.