A facile and scalable method to synthesize high purity α”-Fe₁₆N₂ powders with tunable sphere structures is developed. This strategy combined spray drying of Fe salt particles with hydrogen reduction and subsequent
ammonia nitridation to form α”-Fe₁₆N₂ phase. The solid and hollow sphere structures of precursor particles can be easily tuned by adding ethanol as a directing agent. In addition, the initial structure of Fe spheres is
maintained even after phase transformation process. The resulting particles prepared by optimum condition consist of high purity α”-Fe₁₆N₂ with a phase fraction of 95.52 wt%, showing a coercivity of up to 1471 Oe and
a magnetic energy product of up to 2.25 MGOe at room temperature.