Regulating the phase components and morphology of iron sulfide via high magnetic field for controlled the electromagnetic wave absorption performance

The phase selectivity and morphology of materials is an effective strategy to improve the electromagnetic wave absorption (EMWA). However, the preparation of EMWA materials with both controllable phase component and adjustable morphology remains a great challenge. Herein, a strategy of phase regulation through high magnetic field is proposed to achieve controllable adjustment of the phase and morphology of iron sulfide, thus promoting interface polarization to improve the EMWA performance. When a high magnetic field is introduced into the reaction, the single Fe3S4 phase is gradually evolved into FeS2 due to the action of magnetizing energy, which presents in the form of Fe3S4/FeS2 composite. And with the increase of magnetic field intensity, FeS2 content increases gradually. In addition, the magnetic field also induces the assembly of Fe3S4/FeS2 and tends to be staggered. Due to the regulation of phase and morphology, accompanied by the redistribution of conductive loss and interfacial polarization, so that the EMWA property of iron sulfide is effectively regulated. 9 T sample with a good impedance matching exhibits a minimum reflection loss value of −50.31 dB, and the effective absorption bandwidth (EAB) is extended to 4.5 GHz. This work has important guidance and inspiration for the design of phase and morphology controlled by the high magnetic field, and it has great application potential in regulating EMWA performance.