Challenge to the Synthesis of α''-Fe₁₆N₂Compound Nanoparticle with High Saturation Magnetization for Rare Earth Free New Permanent Magnetic Material

Abstract

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 this α''-Fe16N2 nanoparticles suggest that a new path for a possible candidate of the rare-earth-free permanent magnet material with a high Ms.

Formation and Decomposition of Metastable α′′‐Fe16N2 from in situ Powder Neutron Diffraction and Thermal Analysis

“…[14] Very recently, a report claiming the successful single phase synthesis of αЈЈ-Fe 16 N 2 according to Mößbauer spectroscopy data was presented. [15] The precise study of synthesis conditions of transition metal nitrides and resulting products is hampered for different reasons. In the first place, all transition metal nitrides with exception of the early refractory metal nitrides [16] suffer from low temperature stability and thus exhibit high decomposition pressures at moderate temperatures.…”

Morphology and magnetic properties of α”-Fe₁₆N₂ nanoparticles synthesized from iron hydroxide and iron oxides

“…Since it is still very difficult to produce metastable α"-Fe16N2 in thin films, the synthesis of single phase α"-Fe16N2 in bulk form is considered to be extremely challenging 5,6,7) . In 2013, a procedure for the synthesis of single phase α"-Fe16N2 nanoparticles was established, and α"-Fe16N2 was reported 8) to exhibit Ms ≃ 226 emu/g and Ku ≃ 9.6×10 6 erg/cm 3 at 300 K.…”

Structures, phase transitions, and magnetic properties of Co3Si from first-principles calculations

“…In recent years, considerable efforts have been devoted to discovering rare-earth (RE) free permanent magnet (PM) materials [1][2][3][4][5][6][7][8][9]. New RE free PM materials with enhanced magnetocrystalline anisotropy comparable to that of RE compounds [10][11][12] such as Nd 2 Fe 14 B or SmCo 5 would be of great scientific and technological interest.…”

“…New RE free PM materials with enhanced magnetocrystalline anisotropy comparable to that of RE compounds [10][11][12] such as Nd 2 Fe 14 B or SmCo 5 would be of great scientific and technological interest. Although such a goal is still far from being accomplished, much progress has been made both experimentally due to the development of advanced synthesis techniques [2][3][4][5][6] and theoretically because of the advances in the computational capability to predict new materials with promising magnetic properties [7][8][9].…”