Preparation and Microwave Absorption Properties of Fe3O4Hollow Microspheres

Fe3O4 hollow microspheres with a mean diameter of 525 nm have been synthesized by a facile solvothermal method, which displays an excellent microwave absorption property in the range of 2∼18 GHz as well as with a low density. The microwave absorption is enhanced as the mass fraction of Fe3O4 hollow spheres in the sample increases from 10% to 60%, while the absorption frequency shifts to a lower frequency range. In particular, the maximum reflection loss is −15.8 dB at 7.4 GHz while −10 dB bandwidth of reflection loss achieves 2.6 GHz for the sample with mass fraction of 60%.