Synthesis of Metal Nitride Using Nitrogen Fluid under High Pressure and High Temperature -Synthesis and Physical Property-

Abstract

Synthesis of metal nitrides has been tried in a supercritical nitrogen fluid at high pressures (about 10 GPa) and high temperatures yield using diamond anvil cell and YAG laser heating system. Transition-metal nitrides such as TiN, VN, Fe₂N, ZrN, NbN, MoN and HfN can be easily synthesized by a direct nitriding reaction between metal and fluid nitrogen. Superconducting transition of TiN, VN, ZrN and NbN can be observed using one synthesized sample by a SQUID magnetometer. Colorless transparent fine crystals of GaN in the wultz-rock type structure can be also grown from gallium and fluid nitrogen. They have hexagonal platelet or prismatic morphology, indicating a solution growth using supercritical nitrogen fluid as a solvent. These results in this study open us a new way of synthesis and crystal growth of various kinds of nitrides in a supercritical nitrogen fluid under high temperatures and high pressures yield using diamond anvil cell and YAG laser heating.