Huang Mengqiu, Li Bangxin, Qian Yuetong, Wang Lei, Zhang Huibin, Yang Chendi, Rao Longjun, Zhou Gang, Liang Chongyun, Che Renchao
Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai, 200438, People's Republic of China.
Department of Chemistry, Fudan University, Shanghai, 200438, People's Republic of China.
Nanomicro Lett. 2024 Jul 12;16(1):245. doi: 10.1007/s40820-024-01416-2.
Broadband electromagnetic (EM) wave absorption materials play an important role in military stealth and health protection. Herein, metal-organic frameworks (MOFs)-derived magnetic-carbon CoNiM@C (M = Cu, Zn, Fe, Mn) microspheres are fabricated, which exhibit flower-like nano-microstructure with tunable EM response capacity. Based on the MOFs-derived CoNi@C microsphere, the adjacent third element is introduced into magnetic CoNi alloy to enhance EM wave absorption performance. In term of broadband absorption, the order of efficient absorption bandwidth (EAB) value is Mn > Fe = Zn > Cu in the CoNiM@C microspheres. Therefore, MOFs-derived flower-like CoNiMn@C microspheres hold outstanding broadband absorption and the EAB can reach up to 5.8 GHz (covering 12.2-18 GHz at 2.0 mm thickness). Besides, off-axis electron holography and computational simulations are applied to elucidate the inherent dielectric dissipation and magnetic loss. Rich heterointerfaces in CoNiMn@C promote the aggregation of the negative/positive charges at the contacting region, forming interfacial polarization. The graphitized carbon layer catalyzed by the magnetic CoNiMn core offered the electron mobility path, boosting the conductive loss. Equally importantly, magnetic coupling is observed in the CoNiMn@C to strengthen the magnetic responding behaviors. This study provides a new guide to build broadband EM absorption by regulating the ternary magnetic alloy.
宽带电磁（EM）波吸收材料在军事隐身和健康防护方面发挥着重要作用。在此，制备了金属有机框架（MOF）衍生的磁性碳CoNiM@C（M = Cu、Zn、Fe、Mn）微球，其呈现出具有可调谐EM响应能力的花状纳米微观结构。基于MOF衍生的CoNi@C微球，将相邻的第三种元素引入磁性CoNi合金中以增强EM波吸收性能。就宽带吸收而言，CoNiM@C微球中有效吸收带宽（EAB）值的顺序为Mn＞Fe = Zn＞Cu。因此，MOF衍生的花状CoNiMn@C微球具有出色的宽带吸收性能，EAB可达5.8 GHz（在2.0 mm厚度下覆盖12.2 - 18 GHz）。此外，采用离轴电子全息术和计算模拟来阐明其固有的介电损耗和磁损耗。CoNiMn@C中丰富的异质界面促进了接触区域负/正电荷的聚集，形成界面极化。由磁性CoNiMn核催化的石墨化碳层提供了电子迁移路径，增强了传导损耗。同样重要的是，在CoNiMn@C中观察到磁耦合，以强化磁响应行为。本研究为通过调控三元磁性合金构建宽带EM吸收提供了新的指导。
