Preparation and magnetic properties of nanoscale ɛ-Fe3N particles

In this work, ɛ-Fe3N nanoparticles were synthesized by chemical reaction of iron carbonyl (Fe(CO)5) and ammonia gas (NH3). X-ray diffraction results showed that the nitriding temperature has important effect on the phase composition when all other experimental conditions were fixed. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface composition of the ɛ-Fe3N nanoparticles. The experimental result indicated that the particle surface consists mainly of iron and oxygen in the form of Fe2O3. The average sizes of single-phase ɛ-Fe3N particle were determined by XRD, TEM and BET, respectively, and the results showed that these methods are suitable for the particle size testing within the experimental error. ɛ-Fe3N nanoparticles has lower saturation magnetization and Curie temperature than that of the bulk and the saturation magnetization and Curie temperature decreases with the decreasing particle size. However, the coercivity of the particles increases with the decreasing particle size.