Shock synthesis and characterization of new diamond-like carbon nitrides

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 sp 3-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.