Ultra-high pressure techniques like laser heated diamond anvil cell (LH-DAC) or multi anvil devices have been applied to synthesise novel solid state structures which cannot be produced by other methods, for example, inorganic nitrides.
This technique was found to be the most promising route in the successful synthesis of carbon nitrides. Most recently, we have succeeded in the synthesis of a novel dense crystalline C2N2(NH)-phase at high-pressures and high temperatures using a LH-DAC.
The first spinel nitride, γ-Si3N4, as well as super hard transition metal nitrides were synthesized under high pressure and temperature. In particular, a new family of high-pressure group IV transition element nitrides, namely c-Zr3N4 and c-Hf3N4, having cubic Th3P4-type structure was discovered in our research group.