ε-Fe3N : magnetic structure, magnetization and temperature dependent disorder of nitrogen

Abstract e-Fe 3 N has been investigated by time-of-flight neutron diffraction (temperature range 4.2–618 K) and SQUID magnetometry (2–700 K, B ≤5 T). A ferromagnetic spin structure is observed with magnetic moments oriented perpendicular to the c -axis of the hexagonal nuclear structure. The magnetic saturation moment of iron is 2.2 μ B at 4.2 K from neutron diffraction and 2.0 μ B from magnetic measurements and decreases in a Brillouin-like manner on heating to T C =575 K. Above 450 K an increasing but reversible disorder of the nitrogen partial structure is observed.