Challenge to the synthesis of α"-Fe₁₆N₂ compound nanoparticle with high saturation magnetization for rare earth free new permanent magnetic material

Single-phase α"-Fe₁₆N₂ nanoparticles have been synthesized with high reproducibility in gram amounts for the first time. The nanoparticles were obtained through the various kinds of successive procedure starting from the reduction of Fe-oxides, followed by nitriding in an atmosphere with very low moisture and oxygen contents of less than 1 ppm through the entire process. The single-phase α"-Fe₁₆N₂ nanoparticles exhibited saturation magnetization (Ms) of 234 emu/g at 5 K and a magnetocrystalline anisotropy constant (Ku) of 9:6 - 106 erg/cm3. These magnetic properties of α"-Fe₁₆N₂ nanoparticles suggest that a new path for a possible candidate of the rare-earth-free permanent magnet material with a high Ms.