Electromagnetic shielding effectiveness of amorphous metallic spheroidal- and flake-based magnetodielectric composites
| Autor: | Alexander S. Sokolov, Ogheneyunume Fitchorova, Vincent G. Harris, Yajie Chen, Chengju Yu, Qifan Li, Kun Qian, Piotr Kulik, Chins Chinnasamy |
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| Rok vydání: | 2021 |
| Předmět: |
Permittivity
Materials science Polymers and Plastics Mechanical Engineering Metals and Alloys 02 engineering and technology Coercivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Amorphous solid Ferromagnetism Mechanics of Materials Permeability (electromagnetism) Electromagnetic shielding Materials Chemistry Ceramics and Composites Composite material 0210 nano-technology Polarization (electrochemistry) Ball mill |
| Zdroj: | Journal of Materials Science & Technology. 83:256-263 |
| ISSN: | 1005-0302 |
| Popis: | Flexible, lightweight, conductive materials, having both high rf losses and high permeability, are extremely desirable for applications as electromagnetic (EM) shielding. Gas atomized spherical FeSi-based ferromagnetic metallic particles, having a mean diameter of 14.6 μm with a standard deviation of 7.3 μm, were measured to have a room temperature saturation magnetic flux density of 1.49 T with a coercivity of 160 A/m. Ball milling of the amorphous particles led to aspect ratios from 1:1 (spherical) to > 100:1 (flake-like). Flake-like particles, suspended in paraffin, were found to not only increase the surface area of fillers enhancing the polarization mechanism but also increase the complex permeability and complex permittivity, and thus provide broadband shielding effectiveness. A loading factor of 40 vol.% of the ∼15 μm diameter powders provided the largest ΔWRL = -20 dB of 9.49 GHz (i.e., 6.55 |
| Databáze: | OpenAIRE |
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