Synthesis, magnetic and electrical properties of Fe-containing SiO2 nanocomposite

Nanocrystalline Fe powders were synthesized by transmetallation reaction and embedded in silica to form Fe–SiO2 nanocomposite. Thermomagnetic study of the as-prepared Fe sample indicates the presence of Fe3O4 and Fe particles. Oxidation studies of Fe and Fe–SiO2 show an increased thermal stability of Fe–SiO2 nanocomposite over pure Fe. The Fe–SiO2 shows an enhanced oxidation temperature (i.e., 780 K) and a maximum saturation magnetization value of (135 emu/g) with 64 wt.% of Fe content in silica. Electrical and dielectric behaviour of the Fe–SiO2 nanocomposite has been investigated as a function of temperature and frequency. Low frequency ac conductivity and dielectric constants were found to be influenced by desorptions of chemisorbed moisture. High saturation magnetization, thermal stability, frequency-dependent conductivity and low power loss make Fe–silica a promising material for high frequency applications.