Pressure dependence of electronic structure and magnetic properties in Fe16N2

The electronic structures and magnetic properties of Fe16N2 system and their pressure dependence were investigated by using first-principles calculations based on the density functional theory. It has been found that the total magnetic moment in Fe16N2 system decreases monotonically as increasing pressure from 0 to 14.6 GPa. A phase transition from ferromagnetic (FM) to non-magnetic (NM) occurs with a volume collapse of around 0.008 nm3 at 14.6 GPa, The lattice constants aa and cc for magnetic results decrease monotonically as pressure increasing from 0 to 14.6 GPa, at 14.6 GPa, the lattice constant aa decreases sharply, on the contrary, the lattice constant cc increases abruptly. We think that the change of microscopic structure of Fe16N2 is responsible for the phase transition from FM to NM.

► Total magnetic moment decreases monotonically as pressure increasing from 0 to 14.6 GPa. ► A phase transition from ferromagnetic to non-magnetic occurs at 14.6 GPa. ► A volume collapse of around 0.008 nm3 occurs at 14.6 GPa. ► A sudden jump occurs in lattice constants aa and cc for magnetic results at 14.6 GPa. ► Phase transition from FM to NM should be attributed to the change of microscopic structure of Fe16N2.