Achieving Superior Electromagnetic-Absorbing Performances in the Hexagonal Flake BaFe<sub>12</sub>O<sub>19</sub>@PVDF Composites
C. Q. Chen, Gang Chen, Fei Chen, Zixuan Zhang, Jie Wang, Zhengtang Su, Zhijun Zhou, Yilong Ma, Wei Cai, Rongli Gao
Abstract
Combining magnetic and dielectric materials to form a composite can significantly improve its impedance matching and electromagnetic wave absorption performance. Furthermore, composite materials with a core–shell structure hold promise in meeting the demand for lightweight and highly electromagnetic-absorbing properties. In this study, uniform hexagonal flake barium ferrite (BaFe 12 O 19 ) was prepared using the hydrothermal method. Subsequently, BaFe 12 O 19 @PVDF composites were synthesized by the sol–gel method. By adjusting the mass ratio of BaFe 12 O 19 and PVDF, the shell size of the BaFe 12 O 19 @PVDF composite material was controlled, and its electromagnetic absorption performance was enhanced. The shell thickness of BaFe 12 O 19 @PVDF is 19.64 nm when the BaFe 12 O 19: PVDF mass ratio is 1:1.0, and the optimal impedance matching is obtained at 13.4 GHz. Meanwhile, at a thickness of 1.5 mm, the minimum reflection loss (RL min ) reached −58.04 dB, and an effective absorption bandwidth (EAB) (RL ≤ −10 dB) of 5.53 GHz was achieved within the frequency range of 11.65 to 15.63 GHz and from 16.36 to 17.91 GHz. Besides, the composites with a matching thickness of 3.5 mm show a maximum EAB of 15.90 GHz when the mass ratio of BaFe 12 O 19 to PVDF is 1:1.2. Within the frequency range of 2–18 GHz, the coverage of reflection loss less than −10 dB is 99.38%, almost achieving full coverage. These results demonstrate that BaFe 12 O 19 @PVDF composites exhibit excellent electromagnetic-absorbing performances, making them an excellent candidate for electromagnetic wave absorption in 5G communications.