Computing the iron–nitrogen phase diagram at high pressure and high temperature

Locating pressure and temperature conditions relevant to concurrent diamond-anvil-cell (DAC) experiments is imperative for the discovery of new high–pressure nitrogen-rich compounds. In this work we provide a pressure-temperature phase diagram iron–nitrogen system pressures up 200 GPa temperatures 4000 K through combination Density Functional Theory computations thermodynamic calculations. The includes an assessment chemical potential nitrogen its change at high temperature. We deliver stability fields various Fe–N compounds in presence excess nitrogen. Our results are agreement with recent synthesis FeN2 FeN4, predict hitherto unknown FeN8 attainable 100 1500 K.