The microstructure and magnetic properties of FeCo@SiO2 core-shell nanoparticles synthesized by using a solution method

Abstract

FeCo@SiO2 nanoparticles were prepared by a solution method and annealed in gas mixtures. The influence of annealing temperature and SiO2 shell thickness on the morphology, microstructure and magnetic properties has been checked. After annealing at 450 °C, FeCo@SiO2/0.2 ml nanoparticles with pure FeCo phase show large saturation magnetization of 138.5 emu/g. With the increasing of SiO2 shell thickness, the pure FeCo phase of FeCo@SiO2 nanoparticles was kept, the magnetization decreased and the coercivity increased respectively. These FeCo nanoparticles with large saturation magnetization have great potential in some industry fields.