Ferromagnetic and microwave absorption properties of copper oxide/cobalt/carbon fiber multilayer film composites

The copper oxide/cobalt/carbon fiber multilayer film composites were synthesized by thermal oxidation route. In order to investigate the intrinsic reasons for microwave absorption properties of absorbers, the complex permittivity, complex permeability and the microwave absorption properties of composites were studied in the 1–18 GHz range. The strongest reflectivity loss (RL) of microwave absorber was further enhanced to − 42.7 dB (microwave absorption rate > 99.9%) at 10.8 GHz for a layer of 2.0 mm thickness, and the strong absorption (RL < − 10 dB) was obtained between 8.72 and 18 GHz for the thickness of 1.3–2.2 mm. The results indicated that the dielectric loss and magnetic loss led to the excellent microwave absorption property of CuO/Co/CF composites. It is believed to be ideal for making a lightweight, strong absorption and wide-frequency microwave absorbing material. Highlights ► CuO/Co/CF composites were synthesized by thermal oxidation route. ► Reflectivity loss (RL) of 2-mm thick CuO/Co/CF composites reaches − 42.7 dB at 10.8 GHz. ► RL of 1.3–2.2-mm CuO/Co/CF composites is less than − 10 dB in the 8.72–18 GHz range. ► Dielectric and magnetic losses lead to excellent microwave absorption.