Scalable liquid-phase synthesis of core–shell absorbers: Synergistic dielectric/magnetic losses dominating microwave attenuation
Zhijian Xu, Haoyang Zhan, Chenyang Jing, Qiang Chen, Meng Zhu, Luo Kong, Lechun Deng, Yuchang Qing, Shifeng Wen, Chun‐Hai Wang, Dongmei Zhu, Fa Luo, Hailong Xu
Abstract
Dielectric-magnetic composite material that incorporate both dielectric and magnetic loss mechanisms are progressively emerging as the design paradigm for high-performance EMW absorbing materials. However, it remains challenging to combine dielectric and magnetic materials through a convenient structural design. Here, we report a core-shell structured Fe<sub>3</sub>O<sub>4</sub>@copper sulfide with multiple loss mechanisms, combining the typical magnetic component Fe<sub>3</sub>O<sub>4</sub>, which has excellent magnetic loss and impedance matching, with the dielectric component copper sulfide, which has high electrical conductivity and rich interfaces. Unlike the conventional hydrothermal synthesis method, the Fe<sub>3</sub>O<sub>4</sub>@copper sulfide core-shell structure is formed using the polymer-assisted electrodeless metal deposition (PAMD) method and a subsequent solution based sulfidation reaction. Attributed to the strong dielectric loss capacity introduced by copper sulfide nanosheets, Fe<sub>3</sub>O<sub>4</sub>@copper sulfide has an EAB of 5 GHz within 2-18 GHz at a filling ratio of 65 wt.% and a thickness of only 1.4 mm. In addition, we used the same possess to synthesize FeSiCr@copper sulfide, which also exhibited EMW absorption performance superior to that of the original magnetic component, verifying that the PAMD method is also applicable to other magnetic particles. Therefore, the proposed PAMD method provides a new solution-based strategy for constructing high-performance EMW absorbing materials with multi-component and multi-loss mechanisms.