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. - Highlights: • The hexagonal epsilon-Fe₃N powders were fabricated by the molten salt method. • Epsilon-Fe₃N had good dissipation property in comparison with that of CI. • CI had better impedance matching characteristic than that of epsilon-Fe₃N. • The calculated reflectivity of epsilon-Fe₃N was consistent with the measured value. • The reflectivity of double layer absorber based on epsilon-Fe₃N and CI was studied