“…Iron oxide and oxyhydroxide iron have been extensively used in the production of pigments, catalysts, gas sensors, magnetic recordings, and raw materials for hard and soft magnets [1][2][3][4][5][6][7]. Among the iron oxides, ␣-Fe 2 O 3 has the corundum structure, while ␥-Fe 2 O 3 and Fe 3 O 4 have the spinel structure.…”