Self-assembly hollow magnetoelectric composites emerging tunable property between microwave absorption and shielding with light-weight and broad bandwidth

Abstract

In generally, microwave absorption and shielding are a pair of conjugate properties, which merely achieves in the same system of electro-magnetic materials. In this work, Prussian blue analogues (PBA) derived hollow CoNi@C frames embedding with reduced graphene oxide (rGO) are successfully synthesized through a facile self-assembly method. In addition to considerable dielectric loss originating from high conductivity components of C@rGO, magnetic loss is also impressive due to the dynamic magnetic coupling interaction among the closely spaced magnetic units of CoNi. Finally, the CoNi@C@rGO composite with an extremely low loading ratio of 30 wt% reveals a strong reflection loss of − 48 dB and a broad absorption bandwidth of 6.24 GHz concurrently at a thin thickness of 1.6 mm. The launch field is obviously suppressed by covering the CoNi@C@rGO coating and RCS is below − 10 dBm2 within the entire detection angles (−90°<theta<90°). Meanwhile, superior shielding effectiveness (SE) of 66.2 dB is also achieved in the CoNi@C@rGO composite at 3.59 mm. It demonstrates that our work provides an effective and facile approach to make a transformation between microwave absorption and microwave shielding in the same material system.