Enhanced Dielectric Polarization from Disorder-Engineered Fe3O4@Black TiO2-x Heterostructure for Broadband Microwave Absorption

Abstract Core-shell structure has been attracting considerable interest to enhance microwave absorption due to its distinct designable interface. To broaden absorption bandwidth, it is necessary to integrate semiconductor with magnetic material. However, it still remains a huge challenge to construct such core-shell heterostructure. Herein, a novel core-shell Fe3O4@black TiO2-x (Fe3O4@b-TiO2-x) heterostructure was successfully fabricated via a surface treatment strategy in vacuum. The unique multi-interfacial structure was constructed by a disordered TiO2-x layer tightly wrapping Fe3O4@TiO2 nanostructure, which exhibited a broadband microwave absorption. Typically, the effective absorption bandwidth (RL