Abstract
•Composites of BiFeO3, MWCNTs, and polythiophene were successfully prepared.•Composite with 20 wt% of MWCNTs (named as P@20 MW/BF) has best RL of −19 dB.•Balance of mangetic and dielectric losses enhanced microwave absorption properties.•P@MW/BF composites are potential microwave absorbers for f = 12.4–18 GHz.
No magnetic loss during the absorption process is a lack of conductive polymers, while not lightweight is a drawback of magnetic materials to be potential microwave absorbers. A hybrid of magnetic material and conductive polymer is a good resolution for above issues. In this work, composites of BiFe0.8Co0.1Mn0.1O3 (BF) and multi-walled carbon nanotubes (MWCNTs, named as MW) were prepared by a hydrothermal method. Then, the in-situ polymerization method was used to decorate polythiophene on the MW/BF composites. The formation of polythiophene@MW/BF composites and their magnetic, electromagnetic properties were investigated using XRD, XPS, FE-SEM, EDS, and VNA. The composite with MW and polythiophene significantly tuned the microwave dissipation features of the polythiophene@MW/BF composites. In the measurement range of 12.4–18 GHz, the results revealed that the composite with 20 percent of MW (named as P@20 MW/BF) has a minimum reflection loss of −19 dB at frequency f = 13 GHz for a thickness of 2 mm. The maximum effective absorption bandwidth was also found for the P@20 MW/BF composite as 2.6 GHz. Enhancement in microwave absorption performance arises from the balance between magnetic loss and dielectric loss. Overall, the introduction of three-layer polythiophene/MW/BF composites provides potential microwave absorbers for application in the range of 12.4–18 GHz.