Structural and component optimization of conventional magnetic material Co to synthesis dendritic-like FeCo and rose-like CoNi toward high-performance electromagnetic wave absorption

Abstract

To promote the electromagnetic (EM) wave absorption property of conventional magnetic material Co, we synthesized dendritic-like FeCo and rose-like CoNi by a hydrothermal process. The morphology, structure and magnetic properties results reveal that dendritic-like FeCo is consisted of leaf-like unit layers and rose-like CoNi is composed of nano-sheets, and all samples have ferromagnetic behavior. The absorption intensity of dendritic-like FeCo to EM wave can achieve −36.5 dB at 1.0 mm absorber thickness and the effective absorption bandwidth (EAB) of rose-like CoNi is 5.3 GHz at 1.5 mm absorber thickness, which are far better than conventional magnetic material Co. The EM wave absorption mechanisms reveal that favourable impedance matching, multiple reflection and absorption to EM wave in the unique structure promote dendritic-like FeCo and rose-like CoNi show an excellent EM wave absorption capacity at thin absorber thickness. As a result, excellent EM wave absorbing materials can be obtained by optimizing the composition and structure of Co, and this design strategy can also be used to improve the EM wave absorbing properties of other conventional magnetic materials.