High-frequency magnetic properties of FeNi3-SiO2 nanocomposite synthesized by a facile chemical method

Monodisperse core-shell structured FeNi3-SiO2 composite nanoparticles (NPs) were synthesized by a facile hydrazine reduction combined modified Stober method. SEM and TEM analysis shows that FeNi3 cores are composed of small primary nanocrystals and are coated by amorphous SiO2 layer. As-prepared FeNi3-SiO2 nanocomposites exhibit typical soft magnetic properties. The permeability spectra vary with the contents of SiO2. When the SiO2 content is 10 wt%, the real part mu ' of the permeability reaches about 10 and is almost independent of frequency in the frequency range up to 1 GHz. And the imaginary part mu '' remains very low. This paper presents a facile approach to fabrication of novel soft magnetic materials for high-frequency applications. (C) 2011 Elsevier B.V. All rights reserved.