Designed synthesis of wide range microwave absorption Fe3O4-carbon sphere composite

Fe3O4-carbon sphere composite was synthesized by a simple hydrothermal method. The as-synthesized products were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Raman spectrum. The complex permittivity and permeability of paraffin wax and Fe3O4-carbon sphere composite with different volume fraction of the composite were measured by vector network analysis. A wide region of microwave absorption was achieved due to dual dielectric and magnetic losses. When the matching thickness is 4 mm, the calculated reflection loss of the sample with 70% volume fraction of Fe3O4-carbon sphere composite exhibits a broad microwave absorption ranging from 2.5 to 18 GHz. (C) 2009 Elsevier B.V. All rights reserved.