Controllable synthesis of Fe₃O₄-based magneto-dielectric ternary nanocomposites and their enhanced microwave absorption properties

In order to overcome the drawbacks of Fe₃O₄ composite samples and greatly increase their performance in microwave absorption, magnetic Fe₃O₄ spindles coated with dielectric SnO₂ nanorods and MnO₂ nanoflakes have been successfully synthesized by a four-step simple hydrothermal route. This rationally designed magneto-dielectric ternary nanocomposite will introduce multiple reflection and conductive losses caused by its special multilayer structure and the effective complementarity of dielectric loss and magnetic loss. Therefore, its absorbing performance can be greatly improved. It is notable that the as-prepared Fe₃O₄@SnO₂@MnO₂ nanocomposites show a minimum reflection loss value of −50.40 dB at 17.92 GHz at a thickness of 3.9 mm and the absorption bandwidth ranges from 3.62 to 12.08 GHz. The as-prepared Fe₃O₄@SnO₂@MnO₂ ternary nanocomposite is expected to be a potential candidate for high-performance microwave-absorbing materials with intensive electromagnetic wave absorption and wide effective absorbing bandwidth. (paper)