Synthesis of metastable hard-magnetic ε-Fe ₂ O ₃ nanoparticles from silica-coated akaganeite nanorods

We present a simple preparation route to obtain a nanoscale metastable hard-magnetic ε-Fe2O3 phase, using silica coated β-FeOOH nanorods as a precursor and an annealing process. The synthesized ε-Fe2O3 nanoparticles exhibit large coercivity (HC ∼ 20 kOe at 300 K and HC ∼ 1.6 kOe at 400 K), confirming their high potential for practical applications.