In this study, ultrasonic bath and milling processes were used to synthesis epoxy resin-multiwalled carbon nanotubes (MWCNT) composite, and their effect on the absorption of magnetic waves was investigated using the Vector Network Analyzer (VNA) test. The effect of the concentration of MWCNT used to attract the wave's magnetic part in the epoxy resin matrix is also investigated. This study showed that the optimal amount of MWCNT in this epoxy resin-MWCNT composite was about 5 wt.% for the ultrasonic bath method, while it was around 15 wt% for the milling method. The ultrasonic bath caused the reflection losses (RL) value reaches to about -25 dB in the range of 9 to 11 GHz. The results of the VSM test showed that the composite produced from epoxy resin and MWCNT is a soft magnetic material. Also, the sample produced in the ultrasonic bath process has a higher magnetic saturation than the milling process, which causes it to absorb more electromagnetic waves. Manuscript profile

The structural and magnetic properties of the polyethylene glycol (PEG) coated nickel spinel ferrite (NiFe2O4) nanoparticles have been reported in the present study. NiFe2O4 nanoparticles were prepared by solution plasma method using KOH + Na2Co3 as electrolyte. The prepared powder of nickel ferrite nanoparticles was annealed at 800 ˚C for two h and used for further study. The X-ray analysis confirmed the formation of a cubic spinel single-phase structure. The crystallite size, lattice parameter, and X-ray density of the PEG-coated NiFe2O4 nanoparticles were calculated using XRD data. TEM and FTIR studies revealed the presence of PEG on nickel ferrite nanoparticles and reduced agglomeration in the NiFe2O4 nanoparticles. The pulse-field hysteresis loop tracer technique studied the magnetic properties at room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, and coercivity have been obtained. These magnetic parameters were get decreased by PEG coating. Manuscript profile