[1] HfN is refractory and generally produced as a thin film coating,[2] although zone annealing gives the bulk material.
[2] The surplus hafnium electron delocalizes, so that HfN is a metal, conducting at room temperature and superconducting below 8.8 K (−443.83 °F).
[4] The dark red semiconductor Hf3N4 does not form at room temperature, but requires high pressure, high temperature synthesis in a diamond anvil cell.
At 18 GPa (180,000 atm) and 2,800 K (4,580 °F), it adopts the cubic crystal structure and repeats according to space group I{{{1}}}3d.
Computational studies suggest that it may catalyze polymerization of nitrogen at very high temperatures, through a catenary anion in HfN10.