Magneto-orientated graphite double-layer homo-structure with broadband microwave absorption

Abstract In this work, we utilized magnetic fields as an efficient tool to manipulate the orientation as well as the electromagnetic properties of graphite micro-flakes (GMFs) and first realized the GMFs double-layer homo-structure, which shows excellent EM absorption properties. With tuning the direction of a small magnetic field (850 Gs), vertical and horizontal aligned GMFs are produced. Their electromagnetic parameters are effectively tailored by this magneto-orientation effect and the vertical and horizontal aligned GMFs are good at impedance matching and microwave-loss, respectively. With the combination of those two magneto-orientated layers, vertically oriented as the surficial impedance matching layer and horizontally oriented as the inner loss layer, we design a GMFs-based double-layered homo-structure. After thickness optimization, -38.2 dB minimum reflection loss and 6.4 GHz (11.6–18.0 GHz) absorption bandwidth have been achieved in such magneto-orientated GMFs homo-structure. Our findings further emphasize the importance of materials’ orientation freedom and provide a magneto-strategy to design multiple-layer structures and produce high-performance microwave devices.