Phase Composition and Magnetic Properties of Fe2O3–FeO–Gd2O3 Powders after High-Energy Ball Milling and Thermal Treatment

Resumo

Comprehensive studies of powders with a nominal composition of 90% [43% Fe₂O₃–57% FeO]–10% Gd₂O₃ are performed via scanning electron microscopy, microscopic X-ray spectral and phase analysis, differential scanning calorimetry, and measuring hysteresis properties. It is shown that the main phases in the powders after high-energy ball milling are magnetite (Fe₃O₄) and an amorphous phase; in addition, the powders contain about 2 vol % wustite (FeO) and less than 1 vol % orthoferrite (GdFeO₃). Trends of changes in the phase composition, structure, and hysteresis properties of the annealed powders are identified.