Differentiating two high-pressure phases of Fe3N: a first-principles study

Most of the iron nitride compounds of the type Fe_xN are unstable at ambient pressure and temperature. However, Fe-rich nitrides can be synthesized in a high pressure confined environment. Using a large volume press and X-ray diffraction in combination with scanning electron microscopy techniques, two high pressure phases of Fe₃N were observed with symmetries P6₃22 and P312 [1]. Here we use first-principles calculations based on density functional theory (DFT) to study the structural, electronic, and phase stability properties as a function of pressure of these two iron nitride modifications. The exploration and understanding of high-energy density nitride materials is important as many of them exhibit remarkable technological applications due to their hardness, superconductivity or mechanical traits.

References:

1. Serghiou et al., High Press. Res. 35, 28-36, (2015). doi:10.1080/08957959.2014.996561