Influence of MnO₂ decorated Fe nano cauliflowers on microwave absorption and impedance matching of polyvinylbutyral (PVB) matrix

In this work, a promising, polyvinyl butryl (PVB)-MnO₂ decorated Fe composite was synthesised and microwave absorption properties were studied for the most important frequency ranges i.e., X-band (8.2–12.4 GHz) and Ku-band (12.4–18 GHz). The microwave absorption of Fe nano cauliflower structure can be enhanced by MnO₂ nanofiber coating. 10 wt% Fe–MnO₂ nano cauliflower loaded PVB composite films (2 mm thick) shows an appreciable increase in microwave absorption properties. In X-band, the reflection loss (RL) of this composite decreases almost linearly to −7.5 dB, whereas in the Ku-band the minimum RL was found to be −15.7 dB at 14.7 GHz. Here it was observed that impedance matching is the primarily important factor responsible for enhanced microwave absorption. Further, enhancement of EM attenuation constant ( α ), dielectrics, scattering attenuation also bolsters the obtained results. This polymer composite can be considered as a novel microwave absorbing coating material. (paper)