物理化学学报 >> 2026, Vol. 42 >> Issue (9): 100336.doi: 10.1016/j.actphy.2026.100336

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在多相核壳异质结中协同磁交换共振与多级介电弛豫以实现高效微波耗散

王骏1,2, 王奕博1, 吴吉然1, 王大双2, 刘成1,2,*(), 黄海铭1, 王友勇1, 张传坤1,*()   

  1. 1 湖北汽车工业学院储能与动力电池湖北省重点实验室, 湖北 十堰 442002
    2 湖北汽车工业学院汽车材料学院, 湖北 十堰 442002
  • 收稿日期:2026-04-23 修回日期:2026-05-28 录用日期:2026-05-28 发布日期:2026-07-03
  • 通讯作者: Email: liuc@huat.edu.cn (刘成)zhangchk_lx@huat.edu.cn (张传坤)

Synergizing magnetic exchange resonance and hierarchical dielectric relaxation in multiphase core-shell heterojunctions for efficient microwave dissipation

Jun Wang1,2, Yibo Wang1, Jiran Wu1, Dashuang Wang2, Cheng Liu1,2,*(), Haiming Huang1, Youyong Wang1, Chuankun Zhang1,*()   

  1. 1 Hubei Key Laboratory of Energy Storage and Power Battery, Hubei University of Automotive Technology, Shiyan 442002, Hubei Province, China
    2 School of Automotive Materials, Hubei University of Automotive Technology, Shiyan 442002, Hubei Province, China
  • Received:2026-04-23 Revised:2026-05-28 Accepted:2026-05-28 Published:2026-07-03
  • Contact: Email: liuc@huat.edu.cn (Cheng Liu)zhangchk_lx@huat.edu.cn (Chuankun Zhang)

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摘要：

电磁污染治理与雷达隐身的双重需求持续驱动着高性能宽频微波吸收材料的创新发展。然而，现有过渡金属基体系因趋肤效应存在严重阻抗失配，而传统外源氧化物包覆策略虽能改善阻抗匹配，却会牺牲材料本征磁响应。为解决上述问题，本文采用梯度可控热氧化策略处理气雾化等原子比FeCo合金粉末，制备了氧化程度连续可调的FeCo@(Fe,Co)xO4多相核壳异质结构。氧化程度同时调控核壳比例、多相壳层组成和界面缺陷状态。该原位拓扑化学方法保留了强磁性金属内核，以维持高频磁损耗。同时，衍生的多相半导体壳层优化了阻抗匹配，确保电磁波有效入射。随后，入射能量通过磁–介电协同多重损耗机制被耗散。一方面，功函数梯度诱导的Mott–Schottky内建电场结合氧空位偶极和混合价态Fe2+/Fe3+、Co2+/Co3+电子跃迁网络，精准调控极化弛豫时间，在X至Ku波段激活宽频多级极化耗散。另一方面，粗糙核壳异质界面处形成的高密度界面自旋钉扎阵列，通过磁交换弹簧效应触发强交换共振和自旋摩擦热耗散，构成主导衰减机制。因此，FeCo-450在1.9 mm厚度下实现RLmin = −60.11 dB、EAB = 7.12 GHz的卓越吸波性能，为下一代磁性金属基宽频微波吸收材料设计提供了重要指导。

关键词: 多相核壳异质结构, 强磁-介电协同损耗, 内建电场, 电磁波吸收

Abstract:

Electromagnetic pollution mitigation and radar stealth have driven sustained demand for high-performance broadband microwave absorbing materials. Existing transition-metal-based systems, however, suffer from severe impedance mismatch due to the skin effect, while conventional exogenous oxide-coating strategies improve impedance only at the cost of sacrificing intrinsic magnetic response. To address these limitations, a gradient-controlled thermal oxidation strategy was applied to gas-atomized equiatomic FeCo alloy powder, fabricating FeCo@(Fe,Co)xO4 multiphase core-shell heterostructures with continuously tunable oxidation degree. The oxidation degree simultaneously governs core-shell ratio, multiphase shell composition, and interfacial defect states. This in situ topochemical approach preserves the strongly magnetic metallic core for sustained high-frequency magnetic loss, while the derived multiphase semiconducting shell optimizes impedance matching to ensure efficient electromagnetic wave penetration. The incident energy is subsequently dissipated through a synergistic magnetic–dielectric multi-loss mechanism. On one hand, work-function-gradient-induced Mott–Schottky built-in electric fields, combined with oxygen vacancy dipoles and mixed-valence (Fe2+/Fe3+, Co2+/Co3+) electron hopping networks, precisely modulate the polarization relaxation time, activating broadband multi-level polarization dissipation across the X-to-Ku band. On the other hand, a high-density interfacial spin-pinning array formed at the rough core-shell heterointerface triggers intense exchange resonance and spin-friction thermal dissipation via the magnetic exchange-spring effect–constituting the dominant attenuation mechanism. Consequently, FeCo-450 achieves RLmin = −60.11 dB and EAB = 7.12 GHz at 1.9 mm, offering important guidance for designing next-generation magnetic metal-based broadband microwave absorbers.

Key words: Multiphase core-shell heterostructure, Strong magnetic-dielectric synergistic loss, Built-in electric field, Electromagnetic wave absorption