Microwave absorption performance of ZnFe2O4 nanoparticles coated with carbon and SiO2

Abstract

Previous studies have shown that particle size and core–shell structure have a great impact on the electromagnetic parameters and microwave absorbing performance of materials. Here, ZnFe₂O₄ nanoparticles with a particle size of approximately 4 nm were successfully synthesized using a magnetic field-assisted steam–thermal method at 120 °C. The synthesized ZnFe₂O₄ nanoparticles were coated with silica (SiO₂) and carbon (C). The ZnFe₂O₄@C composite exhibited significantly superior microwave absorption performance, attaining a strong absorption peak of −46.2 dB at 8.80 GHz. We conducted a systematic investigation on their microstructures, electromagnetic parameters and microwave absorption performance. These results not only shed light on the understanding of interfacial effects induced by high-density interfaces formed by ultra-fine particles within the coating but also provide an appealing mode for the implementation of heterogeneous interfacial engineering using coatings.