Parallel‐Orientation‐Induced Strong Resonances Enable Ni Submicron‐Wire Array: an Ultrathin and Ultralight Electromagnetic Wave Absorbing Material

Abstract

Soft magnetic micro/nanostructures are highly desirable for pursuing excellent magnetic properties and electromagnetic wave (EMW) absorption performance. However, their magnetic loss at high frequency is usually very low due to the sharp drop of permeability, and thus results in a heavy loading in matrix and a large layer thickness, which are not conductive to the development of ultralight and ultrathin EMW absorbers. Here, an ultralight and ultrathin EMW absorber based on a parallel Ni wire array are reported, and an orientation‐enhanced strategy to improve EMW absorption performance is proposed. Combining with the finite element simulation, it is found that the parallel orientation of Ni wires with a capacitor‐like structure enhances the interfacial polarization, thereby improving dielectric loss. The strong shape anisotropy caused by orientation increases magnetic loss by enhancing magnetic resonances, which further improves impedance matching. The parallel Ni wire array exhibits excellent EMW absorption and achieves the largest specific reflection loss (reflection loss/(thickness × loading)) among magnetic wire‐based absorbers.

Hierarchical Co/CoO/FeO/C nanocomplex derived from Co(OH)2@NH2-MIL-88 to aid highly efficient microwave absorption

“…The ''real'' part (e 0 , m 0 ) of relative complex permittivity (e r = e 0 À je 00 ) and permeability (m r = m 0 À jm 00 ) is related to the ability of electric and magnetic storage. 37 In contrast, the ''imaginary'' part (e 00 , m 00 ) of e r and m r is related to the loss of the ability of microwave energy. Electromagnetic parameters were obtained by dispersing the Co/CoO/FeO/C-600 nanocomplex in paraffin matrix loading 30 wt%.…”

Co‐Ni Electromagnetic Coupling in Hollow Mo2C/NC Sphere for Enhancing Electromagnetic Wave Absorbing Performance†

“…[ 4‐6 ] Recently, many excellent electromagnetic wave absorbing materials (EWMAs) have been exploited, according to the attenuation mechanism, which consist of nonmagnetic dielectric loss dominant carbon‐based materials and magnetic loss incorporate metallic carbon composites. [ 7‐9 ]…”