Blended and Layered Configurations: Tuning High and Low Frequency Broadband Absorption in Magnetic-Electro Coupling Composites Foam Consisting with Carbonyl iron flaky and Carbon nanotube

Magnetic-electro coupling composites have demonstrated their superiority in the field of electromagnetic wave absorption, but the absorption characteristics and mechanisms of different configuration magnetic-electro coupling composites are misty. In this study, magnetic and electro functional phases of Carbonyl iron flakes (CIF) and Carbon nanotubes (CNT) were combined with a Polystyrene (PS) matrix by one-step physical constraint foaming technology to construct composite foams with blended and layered configurations, respectively. During X-band, the CIF and CNT content remain 50 wt.% and 6 wt.%, the thickness is maintained at 2 mm. The blended configuration CIF/CNT/PS (CIF/CNT) foam demonstrates a 3.22 GHz of absorption bandwidth in relative high frequency, which is wider than 2.72 GHz in relative low frequency for layered configuration CIF/PS-CNT/PS (CIF-CNT) foam. Contrast, the minimum reflection loss value of CIF-CNT is -33.08 dB, which is lower than that of -20.14 dB for CIF/CNT. Due to optimized impedance matching, blended magnetic-electro coupling composites suit high-frequency broadband absorption, while layered configurations with enhanced interfacial reflections/polarization prefer low-frequency strong absorption. Our study provides a significant reference to design magnetic-electro coupling composites to meet requirements of frequency selection absorption characteristics.