Enhanced microwave absorption properties in GHz range of Fe3O4/C composite materials

2-D Fe3O4/C composite materials were synthesized simultaneously through a single heating procedure using sodium chloride salt powder as a sacrificial template. Electromagnetic parameters of composite were measured by a vector network in the range of 2-18 GHz. The obtained composite materials have excellent electromagnetic wave absorption properties. The maximum value of reflection loss of Fe3O4/C-1.0 is -46 dB at 12.8 GHz when the thickness of absorber adjusts to 2.9 mm and the absorbing bandwidth exceeded -10 dB in a broad range from 10.3 to 17.1 GHz. Moreover, the effect of amorphous carbon and magnetite on microwave absorption properties had been studied, respectively. The relationship between the RL peak frequency and the absorber thickness was successfully explained by the quarter-wavelength cancellation. (C) 2015 Elsevier B.V. All rights reserved.