Harnessing Pseudo‐Jahn−Teller Disordering of Monoclinic Birnessite for Excited Interfacial Polarization and Local Magnetic Domains

作者：Xiaogu Huang, Gaoyuan Yu, Bin Quan, Jing Xu, Guomin Sun, Gaofeng Shao, Qinghua Zhang, Tengchao Guo, Jiaping Guan, Mingji Zhang, Xiaohui Zhu, Lin Gu · 发表于：Small Methods · 年份：2023 · DOI：10.1002/smtd.202300045 · 被引用次数：93 · 研究领域：Electromagnetic wave absorption materials、Advanced Antenna and Metasurface Technologies、Multiferroics and related materials

Abstract The symmetry in a polymorph is one of the most important elements for determining the inherent lattice nature. The MnO2 host tends to high‐symmetry MnO6 octahedra as a result of the electronic structure t2g3eg0 of Mn4+ ions, displaying an ordered structure accompanying with poor polarization loss and limiting its application toward high‐performance microwave absorbers. Here, a pseudo‐Jahn−Teller (PJT) distortion and PJT disordering design with abundant self‐forming interfaces and local magnetic domains in the monoclinic birnessite–MnO2 host is first reported. The PJT distortion can give rise to asymmetric MnO6 octahedra, inducing the formation of interfaces and increased electron spin magnetic moment in the lattice. The resultant birnessite with PJT distortions and PJT disordering delivers an outstanding reflection loss value of −42.5 dB at an ultralow thickness of 1.7 mm, mainly derived from the excited interfacial polarization and magnetic loss. This work demonstrates an effective approach in regulating the lattice structure of birnessite for boosting microwave absorption performance.