Constructing dendrite-flower-shaped Fe3O4 crystals in glass-ceramic materials as novel broadband high-efficient electromagnetic wave absorbers

The Snoek limit hinders strong and wideband electromagnetic wave (EMW) absorption, and to meet this challenge, it is essential to obtain an economical and scalable microstructural solution. In this work, we used a SiO2-B2O3-RO-Fe2O3 multicomponent glass system to design microstructures using dendritic Fe3O4 crystal precipitates in the amorphous glass matrix. The flower-like Fe3O4 structures that formed in situ at the grain interface exhibited a significant strengthening effect on EMW absorption performance. The minimum reflection loss (RL) value reached − 61.0 dB at 7.2 GHz when the sample thickness was 3.3 mm, and the effective absorption bandwidth (EAB) was 6.0 GHz (8.6–14.6 GHz), with a sample thickness of 2.4 mm. This approach not only provided a novel strategy for constructing synergistic multiple transmission-absorption mechanisms, but also provided an option for developing inexpensive high-performance EMW-absorbing materials.