Magnetoelectric Heterogeneous Feni-Snox/Carbonized Wood Composite for Ultra-High Performance Electromagnetic Interference Shielding

Abstract

Interface engineering is generally recognized as an effective method for enhancing the performance of electromagnetic interference (EMI) shielding materials. Herein, a novel magnetoelectric heterogeneous wood-based composite (FeNi-SnOx/CW) with ultra-high EMI shielding effectiveness (EMI SE) has been developed through constructing magnetoelectric FeNi-SnOx heterojunctions within carbonized wood framework. The carbonized wood functioned as a conductive and porous scaffold, while the FeNi-SnOx heterojunction significantly increased heterogeneous interfaces, enhancing the polarization and magnetoelectric properties of the material system, thereby boosting EMI shielding. Due to the synergistic effect of multiple mechanisms, the material achieved an excellent conductivity of 437.3 S/m and a high saturation magnetization of 13.33 emu/g, while simultaneously demonstrated an ultra-high EMI SE of 91.3 dB across the X-band (8.2-12.4 GHz) at 2 mm thickness, corresponding to a normalized EMI SE of 455 dB/mm. Surface modification with PDMS to impart hydrophobicity to the FeNi-SnOx/CW composite had minimal impact on its EMI SE, which remained at 81 dB (normalized EMI SE of 405 dB/mm). This research elucidates the potential of FeNi-SnOx heterojunction in enhancing EMI shielding capabilities and provides a strategic approach for using wood-based materials in the development of ultra-high performance EMI shielding materials.

Keywords: carbonized wood, heterojunction, electromagnetic shielding, interface engineering, polarization loss