Interface-induced dual-pinning mechanism enhances low-frequency electromagnetic wave loss

• Published in: Nature communications Vol. 15; no. 1; p. 3299
• Main Authors: Cai, Bo, Zhou, Lu, Zhao, Pei-Yan, Peng, Hua-Long, Hou, Zhi-Ling, Hu, Pengfei, Liu, Li-Min, Wang, Guang-Sheng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.04.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301; 639/301/119/995; 639/925; Absorption; Anisotropy; Attenuation; Bias; Bismuth compounds; C band; Communication technology; Core-shell structure; Design; Dipoles; Electric fields; Electromagnetic radiation; Ferromagnetism; Fourier transforms; Humanities and Social Sciences; Impedance; Impedance matching; Low frequencies; Magnetic moments; multidisciplinary; Nickel ferrites; Optimization; Permeability; Pinning; Polypyrroles; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47537-5

Improving the absorption of electromagnetic waves at low-frequency bands (2-8 GHz) is crucial for the increasing electromagnetic (EM) pollution brought about by the innovation of the fifth generation (5G) communication technology. However, the poor impedance matching and intrinsic attenuation of material in low-frequency bands hinders the development of low-frequency electromagnetic wave absorbing (EMWA) materials. Here we propose an interface-induced dual-pinning mechanism and establish a magnetoelectric bias interface by constructing bilayer core-shell structures of NiFe 2 O 4 (NFO)@BiFeO 3 (BFO)@polypyrrole (PPy). Such heterogeneous interface could induce distinct magnetic pinning of the magnetic moment in the ferromagnetic NFO and dielectric pinning of the dipole rotation in PPy. The establishment of the dual-pinning effect resulted in optimized impedance and enhanced attenuation at low-frequency bands, leading to better EMWA performance. The minimum reflection loss (RL min ) at thickness of 4.43 mm reaches -65.30 dB (the optimal absorption efficiency of 99.99997%), and the effective absorption bandwidth (EAB) can almost cover C-band (4.72 ~ 7.04 GHz) with low filling of 15.0 wt.%. This work proposes a mechanism to optimize low-frequency impedance matching with electromagnetic wave (EMW) loss and pave an avenue for the research of high-performance low-frequency absorbers. This paper proposes a dual-pinning mechanism induced by a magneto-electric bias interface and uses it to designs a double-layer core-shell structure, demonstrating that the mechanism improves electromagnetic wave absorption in the low-frequency bands.