High pressure synthesis and characterization of noble metal nitride IrNx

Novel iridium nitrides (IrNx) have been synthesized from a double decomposition reaction between IrCl3 and Li3N powders under high pressure (5 GPa) and high temperature (1273 K) conditions. X-ray diffraction and Raman spectra analysis reveals that the as-synthesized IrNx have a cubic crystal structure. The lattice constants of IrNx are 4.06 A. The x-ray photoelectron spectrum indicates the N content (x) in IrNx is 0.3. The first-principles calculations further suggest that iridium nitride is face-centered cubic structure, which has not ever been reported experimentally. Such structure is mechanical stable even under 10 GPa and 1273 K conditions. 2013 Elsevier B.V.