Core-shell structured BFO/CFO nanocomposites for efficient microwave absorption

Journal article, 2025

Numerous core–shell nanostructures have demonstrated exceptional microwave-absorption performance, whereas core–shell BiFe3O4(BFO)/CoFe2O4(CFO) nanocomposites have received limited attention. This study highlights microwave-absorption properties of core–shell structured BFO/CFO nanocomposites developed via a low-cost facile Sol-gel technique. X-ray diffraction (XRD) analysis confirmed the coexistence of rhombohedral BFO and cubic-spinel CFO phases, whereas high-resolution transmission electron microscopy (HRTEM) revealed a well-defined core–shell morphology with distinct BFO-CFO interfaces in the nanocomposites. The optimized CFO loading in the nanocomposites improves interfacial polarization and impedance-matching, leading to stronger microwave-absorption and wide effective absorption bandwidth (EAB). Minimum reflection-loss (RLmin) of −35.1 dB (99.97 % absorption) and EAB of ∼ 4.4 GHz were recorded for 50 wt% CFO sample at narrow (1.7 mm) matching-thickness.