Design of rich defects carbon coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites for broadband electromagnetic wave absorption

The precise construction of abundant heterointerfaces and defects in manganese ferrite for efficient electromagnetic wave (EMW) absorption is highly appealing, yet remains a grand challenge. Herein, we report a class of carbon-coated MnFe2O4/LaMnO3/LaFeO3 heterostructure nanocomposites with foam-like porous structures for enhancing EMW absorption. The optimized sample (the molar ratio of Mn:Fe:La is 1:2:1) delivers extraordinary absorption performance of the minimum reflection loss reaches −68.25 dB at 4.24 GHz, along with the maximum effective absorption (RL ≤ -10 dB) bandwidth is 12.26 GHz (3.11–15.37 GHz) at a thickness of 3.9 mm. EMW absorption mechanism reveals that the multiple polarizations induced by adjustable heterointerfaces and abundant defects in spinel/perovskite nanocomposites enhance its dielectric loss capacity, resulting in impressive EMW absorption performance. Moreover, the amorphous carbon shell further optimizes impedance matching. This study not only provides a good reference for future preparation of microwave absorbing materials with rich heterogeneous interfaces and defects but also broadens the application of such kinds of carbon-coated spinel/perovskite nanocomposites.