Enhanced Microwave Absorption Bandwidth in Graphene-Encapsulated Iron Nanoparticles with Core-Shell Structure

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetics

Background:

• Graphene-encapsulated iron nanoparticles (Fe(G)) combine dielectric loss from graphene and magnetic loss from iron.
• This synergistic effect makes them promising for microwave absorption applications.

Purpose of the Study:

• To investigate the microwave absorption properties of Fe(G) nanoparticles.
• To evaluate Fe(G)/paraffin composites for their potential as microwave absorbers.

Main Methods:

• Transmission electron microscopy (TEM) for structural analysis.
• Measurement of complex permittivity and permeability.
• Simulation using transmit-line theory and experimental validation using the Arch method.

Main Results:

• Fe(G) exhibited distinct dielectric behavior due to interfacial polarization.
• Fe(G)/paraffin composites achieved a minimum reflection loss of -58 dB at 11 GHz with 60 wt% loading.
• A wide absorption bandwidth (<-10 dB) of approximately 11 GHz was observed.

Conclusions:

• Graphene-coated iron nanoparticles provide a suitable electromagnetic match for intense microwave absorption.
• Optimizing layer numbers and Fe(G) loading in composites yields excellent microwave absorbers.