M-Type Barium Hexaferrite-Based Nanocomposites for EMI Shielding Application: a Review

The electromagnetic radiation emission at high radio frequency causes electromagnetic interference (EMI) which is a serious issue. EMI shielding materials are necessary to shield the incoming electromagnetic waves to prevent this problem. Hence, the advancement of high-performance EMI absorbers with flexibility, strong absorption, and extensive bandwidth has gained great attention. Recently, M-type barium hexaferrite as EM interference absorber has gained much interest, owing to their high magnetic loss, high saturation magnetization, flexibility, low cost, high Curie temperature, and strong absorption. Furthermore, due to high density, the incorporation of other dielectric loss fillers such as conductive polymers, graphene, and carbon nanotubes are studied as an essential way to improve the microwave’s absorption. In this review, we present the EMI theory and also summarize modern improvements in the fabrication of barium hexaferrite-based materials comprising substituted barium ferrite and chemical integrations with conductive polymers, graphene, CNTs, and multicomponent composites. The key points of increasing the EMI absorption in barium hexaferrite-based materials are to regulate the EM properties, improving the impedance match, and expanded the loss mechanisms.