Structural and magnetic characterization of the ball-milled α-Fe2O3–Mn2O3 and α-Fe–Mn2O3 systems

Abstract In this work, the (Fe2O3)x(Mn2O3)1−x and Fey(Mn2O3)1−y systems were mechanically processed in a high-energy ball-mill. The as-milled powders were structurally and magnetically characterized by X-ray diffraction, Mossbauer spectroscopy and magnetic measurements. Under similar milling settings and conditions, dissimilar behaviors were observed in the studied systems. In the oxide–oxide system, only the bixbyite (Mn,Fe)2O3 phase was obtained in all the analysed samples, whereas in the metal–oxide system, a sharp compositional dependence for the final milling products was observed. For y⩽0.40, the FeMn2O4 spinel phase was detected and, for y>0.40, a wustite-like phase of the (Fe, Mn)1−yO type was formed. It was observed that magnetization in both systems increased with the nominal concentration, x or y, of the magnetic precursors, up to half of the concentration maximum and then it decreased as a result of structural phase transformations.