Microwave absorption performance of the absorber based on epsilon-Fe3N/epoxy and carbonyl iron/epoxy composites

The hexagonal structure epsilon-Fe3N powders were fabricated by the molten salt method. It is found that epsilon-Fe3N exhibited much better electromagnetic attenuation performance, but its impedance match characteristic was worse than that of carbonyl iron based on the database of electromagnetic parameters. Reflection loss of the monolayer absorber for epsilon-Fe3N/epoxy composite obtained by theoretical calculation was in good consistent with that by experiment measurement. The maximum reflection loss of epsilon-Fe3N/epoxy composite was -7.6 dB at 7.28 GHz with a thickness of 2 mm, and the -6 dB absorbing bandwidth was 3.7 GHz. Furthermore, microwave absorbing properties of the double-layer absorber with epsilon-Fe3N/epoxy as the absorbing layer and carbonyl iron/epoxy as the matching layer were investigated. The double-layer absorber had much better microwave absorbing performance. The maximum reflection loss was -49.8 dB at 12.62 GHz, and the bandwidth bellow -6 dB was as much as 14 GHz with a total thickness of 1.4 mm. (C) 2014 Elsevier B.V. All rights reserved.