LOW-TEMPERATURE ROUTES TO EARLY TRANSITION-METAL NITRIDES

Thermal initiation of the reaction of lithium nitride with anhydrous t ransition-metal halides produces crystalline transition-metal nitrides of various compositions M(x)N(y) (M = Y, La, Ti, Zr, Hf, V, Nb, Ta, C r or Mn) via an exothermic solid-state metathesis reaction. Reaction o f anhydrous late transition-metal halides with lithium nitride produce s the metal (M = Mo, W, Fe, Co, Ni, Cu, Pt, Zn or Cd), dinitrogen and lithium halide. The metal nitrides were purified by tetrahydrofuran tr ituration and characterised by X-ray powder diffraction, scanning elec tron microscopy, energy dispersive analysis with X-rays, magnetic mome nt measurements, FTIR spectroscopy and microanalysis.