Constructing 3D Interconnected Fe@Graphitic Carbon Structure for Highly Efficient Microwave Absorber
High-performance microwave absorption materials (MAMs) are attractive for eliminating the pollution and interference of undesired electromagnetic wave. Carbon/magnetic nanocomposites have been regarded as effective microwave absorbers owing to their synergetic effect between dielectric and magnetic loss. However, the complicated synthetic methods limit their applications in MA field. In this work, 3D interconnected Fe@graphitic carbon (Fe@GC) structure is synthesized via a facile two-step method, precipitation and chemical vapor deposition. Fe@GC shows the optimal Reflection loss of -42 dB at 12.72 GHz with a layer thickness of 2.0 mm and the effective absorption bandwidth of 6.72 GHz from 11.28 ~ 18.00 GHz. The outstanding MA properties are owing to multiple reflection behavior, synergetic effect of magnetic and dielectric loss, and the favorable impedance matching. Especially, the abundant interfaces between Fe cores and GC play important roles in enhancing dielectric loss. Meanwhile, the favorable impedance matching implies that more electromagnetic energy can be absorbed and converted to heat or other energy as much as possible.