Fabrication of Mn0.4Zn0.6Fe2O4/Microcrystalline graphite nanocomposites with tunable and efficient microwave absorption

Abstract

Combining magnetic loss materials with carbon-based substances is widely considered an efficient approach to synthesizing high-performance microwave absorbing materials (MAMs). Herein, natural microcrystalline graphite, which has abundant reserves but confined application throughout the world, was employed as the carbon source to synthesize Mn0.4Zn0.6Fe2O4/microcrystalline graphite (MZF/MG) nanocomposites for microwave absorption by a novelty and promising high-temperature mechanochemical method (HTMC). The morphology, chemical compositions, static magnetic properties, electromagnetic wave absorption (EMWA) performances in 2–18 GHz, as well as the EMWA mechanisms of the composites, were comprehensively explored. The experimental results indicate that the addition of MG has a positive effect on the improvement of the EMWA performance of MZF. By varying the MG content and matching thickness of the MZF/(5–20)MG composite, their EMWA properties can be easily adjusted. Among them, the MZF/15MG composite achieves a minimum reflection loss (RLmin) of −42.1 dB (corresponding to 99.994 % of the EMWA) and an effective absorption bandwidth (EAB, RL < -10 dB) of 3.94 GHz (12.54–16.48 GHz) with a matching thickness of 1.3 mm. This study is anticipated to provide an insightful proposition for HTMC and MG being applied to the field of fabricating effective MAMs.