A new and simple route to prepare γ-Fe2O3 with iron oxide scale

Herein we demonstrate a new, reproducible, and facile strategy to prepare γ-Fe2O3 with iron oxide scale by pre-treated with molten sodium hydrate, hydrolysis and subsequent heat treatment method. The structural, chemical composition, morphological, optical, magnetic properties as well as possible transformation mechanism were investigated. X-ray diffraction (XRD), UV-vis diffuse reflectance spectra and X-ray photoelectron spectroscopy (XPS) confirm that the tetragonal γ-Fe2O3 phase with lattice parameters a = 8.3477 Å and c = 25.1823 Å was prepared. For the phase transformation process, the mixture of iron oxide scale and NaOH formed intermediate α-NaFeO2 in the calcined process, then the structure of FeO4 was generated in the hydrolysis procedure. The prepared γ-Fe2O3 have saturation magnetization of 9.03 emu/g and coercivity 322.8 Oe.