Designing Symmetric Gradient Honeycomb Structures with Carbon-Coated Iron-Based Composites for High-Efficiency Microwave Absorption
Yuxin Zhang, Shuhao Yang, Yue Xin, Bo Cai, Pengfei Hu, Haiyang Dai, Chenming Liang, Yuntong Meng, Jihao Su, Xiao-Juan Zhang, Min Lü, Guang-Sheng Wang
Abstract
Abstract The impedance matching of absorbers is a vital factor affecting their microwave absorption (MA) properties. In this work, we controllably synthesized Material of Institute Lavoisier 88C (MIL-88C) with varying aspect ratios (AR) as a precursor by regulating oil bath conditions, followed by one-step thermal decomposition to obtain carbon-coated iron-based composites. Modifying the precursor MIL-88C (Fe) preparation conditions, such as the molar ratio between metal ions and organic ligands (M/O), oil bath temperature, and oil bath time, influenced the phases, graphitization degree, and AR of the derivatives, enabling low filler loading, achieving well-matched impedance, and ensuring outstanding MA properties. The MOF-derivatives 2 (MD 2 )/polyvinylidene Difluoride (PVDF), MD 3 /PVDF, and MD 4 /PVDF absorbers all exhibited excellent MA properties with optimal filler loadings below 20 wt% and as low as 5 wt%. The MD 2 /PVDF (5 wt%) achieved a maximum effective absorption bandwidth (EAB) of 5.52 GHz (1.90 mm). The MD 3 /PVDF (10 wt%) possessed a minimum reflection loss ( RL min ) value of − 67.4 at 12.56 GHz (2.13 mm). A symmetric gradient honeycomb structure (SGHS) was constructed utilizing the high-frequency structure simulator (HFSS) to further extend the EAB, achieving an EAB of 14.6 GHz and a RL min of − 59.0 dB. This research offers a viable inspiration to creating structures or materials with high-efficiency MA properties.