Magnetic spinel manganese ferrite nanocrystal carbon nanotube thin mats with improved electromagnetic shielding performance

Design and fabrication of an effective, affordable, and lightweight material to solve the electromagnetic interference (EMI) problem, through improving the microwave absorption, have become an urgent need during the present period of fast growth of electronic devices and wireless telecommunication technology. Manganese ferrite MnFe₂O₄ nanoparticles (MFO NPs) with three different particle sizes were synthesized using the hydrothermal reaction technique. The MFO NPs were then mixed with carbon nanotubes (CNTs) to fabricate a new EMI shielding mat, through a free polymer-binder surface-engineered tape-casting (SETC) method. The fabricated CNTs-MFO mats have demonstrated superior EMI shielding in the X-band. CNT-only mat (with 48 µm thickness) had a total effective shielding (SE_All), absorption shielding (SE_A), and reflection shielding (SE_R) of 36 dB, 23 dB, and 10 dB, respectively. SE_All of 36 dB proves that the CNT-only mat is a promising material for microwave absorbing materials. However, 1 wt.% of CNTs-MFO-1 has enhanced the SE_All by 14.5% at a frequency of 10.51 GHz. This improvement in SE_All is because of the MFO’s magnetic properties and the heterogeneous structure created by the MFO within the CNT mat, which enhances the EM wave’s absorption.