Enhanced electromagnetic characteristics of carbon nanotubes/carbonyl iron powders complex absorbers in 2–18GHz ranges

Effect of liquid-solid ratio on the morphology, structure, conductivity, and electromagnetic characteristics of iron particles

“…According to the loss mechanism, the dielectric loss can be classified in conductance loss (tg c ), dielectric relaxation loss (tg rel ), resonance loss (tg res ), and so on [1], which strongly depends on the size, morphology, conductivity, polarization model and so forth [7]. In the light of the equation tg  c =1.8×10 10   /f r [16], the irregular iron particles with high conductivity have high conductance loss.…”

“…Based on the above electromagnetic parameters at the given frequency, the reflection loss (R L ) are calculated according to transmission line theory [1,20]. Observed from Figure 6, when the volume fraction (30 vol%) of the absorbent and the coating thickness (1.0 mm) remain unchanged, the reflection loss curves gradually shift to the low frequency with the increasing .…”

“…As conventional EM-wave absorbing materials, iron has received considerable attentions because of its high saturation magnetization and permeability value, which is available for the preparation of the thin absorption coating [1][2][3][4][5][6]. However, fatal disadvantage of high density makes it very difficult to satisfy the demand of lightness for the absorption coating.…”

“…When frequency and coating thickness are certain, excellent light-quality absorption coating may be obtained via a combination of a decrease in the volume fraction of the absorbent and an increase in electromagnetic parameters [1,2]. For this purpose, electromagnetic parameters have been modulated by variation of composition, grain size, volume fraction, and morphology of the absorbers.…”

High yield synthesis of electrolyte heating assisted electrochemically exfoliated graphene for electromagnetic interference shielding applications

“…The realistic approach to address such issues and their legitimate solution for EMI problem is to search a material which exhibits moderate electrical conductivity and high dielectric loss. 5,6 Therefore, in past, a range of materials including very thin sheets of metals, different forms of carbon, 7,8 e.g., single or multi-walled carbon nanotubes (CNTs), 4 carbon bers, 9,10 graphite and its new exotic forms 11,12 such as expanded graphite, 13 reduced graphene oxide (rGO), 14 carbon black, 15 graphene, 12 conducting polymers, dielectric, magnetic materials and their composites have been used for EMI shielding in automobile applications. At present, graphene is the main hub for scientic and industrial community due to their potential applications in many areas, including EMI shielding.…”