Reduction synthesis of FexOy@SiO2 core-shell nanostructure with enhanced microwave-absorption properties

Fe3O4@SiO2 core-shell nanostructures with different core diameter and shell thicknesses were prepared by modified stober method and then converted into FexOy@SiO2 by H-2. The structure, morphology and electromagnetic properties of FexOy@SiO2 core-shell nanostructures were investigated. Experimental results demonstrate that the as-prepared FexOy@SiO2 nanoparticles with deeply reduction not only exhibit significantly enhanced magnetic properties with maximum saturation magnetization values of 76.032 emu/g vs. 50.310 emu/g of Fe3O4@SiO2 core-shell spheres, but also show enhanced microwave absorption properties with the maximum reflection loss value of -23 dB at 9.2 GHz under a thickness of 2.5 mm, which give forceful evidences that these FexOy@SiO2 core-shell nanomaterials are attractive materials for microwave absorption applications. (C) 2014 Elsevier B. V. All rights reserved.