Effect of excessive thickness on microwave absorption performance in SrFe12O19/MWCNT composite materials

This research examines the influence of excessive material thickness on the microwave absorption efficiency of SrFe 12 O 19 /MWCNT composite materials, emphasizing their electromagnetic properties within the X-band frequency range (8–12 GHz). The synthesis of the composites was performed using high-energy ball milling (HEBM) and chemical vapor deposition (CVD) techniques, followed by comprehensive characterization of their structural, magnetic, and dielectric attributes. The study identified an optimal material thickness of 4 mm, achieving maximum reflection loss (RL) efficiency, with a minimum RL of − 1.16 dB was observed for Sample S3 at a thickness of 6 mm in the X-band (8–12 GHz) in MWCNT-integrated samples. Incremental increases in thickness beyond 4 mm led to reductions in microwave absorption performance, attributed to absorption peak shifts and reduced electromagnetic matching efficiency. Magnetic characterization revealed significant reductions in saturation magnetization ( M s ) and retentivity ( M r ) in MWCNT-incorporated samples due to structural alterations, while coercivity ( H c ) was primarily influenced by grain size and synthesis parameters. Dielectric analysis highlighted the enhancement of dielectric loss ( ε ″) driven by interfacial polarization and MWCNT distribution, particularly at lower frequencies. These findings show the critical interdependence of material thickness, magnetic, and dielectric properties in optimizing radar-absorbing materials, offering key insights for the advancement of composite nanostructures in electromagnetic wave absorption applications.