Shock synthesis and characterization of new diamond-like carbon nitrides

Abstract

New diamond-like carbon nitrides (C–N heterodiamonds), no less hard than diamond, have been synthesized for the first time in bulk form by shock compression of graphitic carbon nitride precursors in the dynamic pressure–temperature range around 30 GPa–3000 K. Typically, the C₂N heterodiamond obtained from graphitic C₃N₂ consists of sp³-bonded carbon and nitrogen atoms, belongs to a diamond crystal system, has a lattice constant of 0.351 ± 0.001 nm, 1.6–1.9% smaller than that of diamond, is able to scratch the surface of a sintered-diamond and is very IR active due to the dipole moment of the C–N single bonds. These properties suggest that it could be slightly harder than diamond.