Carbon( IV ) Nitride C3N4— A New Material Harder Than Diamond?

Numerous complex interacting factors complicate the prediction of the existence, structure, and properties of solid‐state compounds. No success crowned the efforts to synthesize a compound of composition C3N4 having a β‐Si3N4 structure, which should have the hardness and stability of diamond. Recently Lieber et al. managed to prepare a CN solid that, though its defined composition is not C3N4, probably does have the postulated β‐Si3N4 structure and exceptional material properties.