Magnetic manganese-based composites with multiple loss mechanisms towards broadband absorption

The weak dielectric properties and the lack of magnetic loss of manganese-based absorbers are obstructed as the new generation of electromagnetic wave absorption (EMA) materials applying in microelectronic devices. Herein, the sulfuration and subsequent compounding strategies have been employed to enhance the EMA performance of multi-shell nanosphere-shaped Mn₂O₃ materials. With the narrow bandgap, the as-obtained MnS possesses reinforced electrical conductivity, which is conducive to conductivity loss. More importantly, the presence of potential difference between different phases will form space charge region at the heterogeneous interface, thus favoring interfacial polarization. Additionally, the improvement of magnetic loss is attributed to the presence of Co₃O₄ nanoparticles. Consequently, the composites present enhanced EMA performance than original Mn₂O₃. Specifically, the minimum reflection loss of as-prepared composites is −51.4 dB at the thickness of 1.8 mm and the broad effective absorption bandwidth reaches 6.2 GHz at 1.9 mm. The low matching thickness and high absorption efficiency in this work can provide a convincing reference when designing distinguished manganese-based absorbers.