Magnetic, Structural and Morphological Properties of Mechanically Alloyed FeSi and FeSiO₂ Nanocomposites

Abstract

Nanostructured FeSi and FeSiO₂ nanocomposites were synthesized via mechanical alloying to investigate the effects of milling time (0–30 h) on their structural, morphological, and magnetic properties. Comprehensive characterization was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). XRD analysis revealed a transition to a disordered FeSi solid solution with a body-centered cubic structure after prolonged milling, alongside a crystallite size reduction and increasing lattice strain. For FeSi, the lattice parameter increased from 0.2861 nm (unmilled) to 0.452 nm after 30 h, with an average crystallite size of 22 nm. In contrast, the FeSiO₂ nanocomposite exhibited crystallite sizes ranging from 79–28 nm, with Fe/SiO₂ showing a lattice parameter decrease from 0.286 nm to 0.283 nm. Morphological evolution was evident through SEM. Magnetic properties improved with extended milling, with FeSi attaining its highest coercivity, saturation magnetization, and remanent magnetization at 30 h. Similarly, FeSiO₂ exhibited notable coercivity and remanence values, with Fe/SiO₂ achieving the highest saturation magnetization of 177.08 emu/g. These results emphasize the potential of FeSi and FeSiO₂ nanocomposites for high-frequency magnetic applications.