Influence of NiFe Alloy Nanopowder on Electromagnetic and Microwave Absorption Properties of MWCNT/Epoxy Composite

Nanocomposite absorbers based on dielectric/magnetic materials are prepared by in situ incorporation of MWCNTs and NiFe alloy nanopowder into epoxy matrix. SEM micrographs and EDAX studies of these nanocomposites clearly revealed the incorporation of MWCNTs/NiFe nanoparticles in the epoxy matrix. Dielectric measurement revealed that the real part of permittivity and permeability of NiFe-filled MWCNT composites increased with an increase in NiFe concentration. The consolidated loss tangent values revealed that the total losses were highest for 15% of NiFe alloy nanopowder, thus accounting for the highest absorption loss. The two-layer RAS composed of NiFe alloy nanopowder-filled MWCNTs/epoxy composite achieves a minimum reflection loss of -12 dB (95% of absorption) in the range of 8.2-9.8 GHz and a maximum peak of -19 dB at 8.2 GHz with a thickness of 4 mm for 15 wt% NiFe alloy nanopowder MWCNTs/epoxy composites. In addition, -10 dB absorption bandwidths of composite material are