Controlled Synthesis, Microstructure Evolution, and Soft Magnetic Properties of Flaky Iron Nitride

Ball milling treatment facilitates the transformation of carbonyl iron powders from a spherical to a flaky morphology, while simultaneously introducing numerous defects that approach the nanometer scale in one dimension. Flaky iron nitride was synthesized via the gas nitridation in an NH3/N2 atmosphere. The microstructure, morphology, and magnetic properties of the samples nitrided at different temperatures were characterized using XRD, SEM, TEM, and VSM. The formation of γ′-Fe4N and ε-Fe3N phases impedes domain wall movement, resulting in a slight increase in the Hc of the samples. Notably, γ′-Fe4N positively influences the magnetic properties of iron nitride. As the nitriding temperature rises, the content of the γ′-Fe4N phase initially increases before subsequently declining. Consequently, the flaky iron nitride synthesized at 610 °C exhibits excellent soft magnetic properties with a high Ms value reaching up to 177.1 emu/g and a low Hc value, indicating its potential applications in the field of magnetic materials.