Structural, electrical and EMI shielding property of carbon nanotube decorated magnetic/ceramic nanoparticles

To protect against harmful electromagnetic interference (EMI), it is crucial to fabricate composite with high total electromagnetic shielding efficiency (SE_T); In this study, FeNi₃-NiFe₂O₄-SiO₂ nanoparticles (NPs) were synthesized using one-pot method and decorated on carbon nanotube's (CNT) sidewall. The final product was magnetic-ceramic/conductive (FeNi₃-NiFe₂O₄-SiO₂/MWCNT) nanocomposite. The EMI shielding characteristic of FeNi₃-NiFe₂O₄-SiO₂ NPs and FeNi₃-NiFe₂O₄-SiO₂/MWCNT nanocomposite was investigated in the range of X and Ku frequency band. The results indicated the high total shielding effectiveness of the FeNi₃-NiFe₂O₄-SiO₂/MWCNT nanocomposite with a thickness of 3.5 mm which was 25dB (SE_T>20dB ~ 90%) at an entire frequency band. The EMI shielding effectiveness of nanocomposite was higher than that of nanoparticles, because of the multi wall carbon nanotube (MWCNT) improved the AC conductivity of nanoparticles. Overall, The FeNi₃-NiFe₂O₄-SiO₂/MWCNT nanocomposite is a promising shielding material which prevents from passing 95% of incident wave through itself.