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.

Key influence factors in magneto-controlled motion of micro-nano graphite flakes

“…In our previous work, it was found that the validity of magnetocontrolling is not only related to B and ∇B, but also to the shape of the material itself [22,29]. In this work, we tried to explore the shape factor effect on the magneto-controlled motion in detail.…”