Cole—Cole Diagram and the Distribution of Relaxation Times

Fang, P. H.

doi:10.1063/1.1695743

Cited by 103 publications

(35 citation statements)

References 6 publications

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“…A plot of   versus   is shown in Fig. S4 in the ESM, in which a single semicircle is denoted as a Cole-Cole semicircle, indicating a Debye relaxation process [59]. There are three semicircles over the entire curve.…”

Section: Emu/g) the Fe 3 O 4 @ N-doped Carbon Nanochains Possess A Hmentioning

confidence: 99%

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

et al. 2018

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Yolk-shell Fe 3 O 4 @N-doped carbon nanochains, intended for application as a novel microwave-absorption material, have been constructed by a three-step method. Magnetic-field-induced distillation-precipitation polymerization was used to synthesize nanochains with a one-dimensional (1D) structure. Then, a polypyrrole shell was uniformly applied to the surface of the nanochains through oxidant-directed vapor-phase polymerization, and finally the pyrolysis process was completed. The obtained products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and thermogravimetric analyses (TGA) to confirm the compositions. The morphology and microstructure were observed using an optical microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM). The N 2 absorption-desorption isotherms indicate a Brunauer-Emmett-Teller (BET) specific surface area of 74 m 2 /g and a pore width of 5-30 nm. Investigations of the microwave absorption performance indicate that paraffin-based composites loaded with 20 wt.% yolk-shell Fe 3 O 4 @N-doped carbon nanochains possess a minimum reflection loss of −63.09 dB (11.91 GHz) and an effective absorption bandwidth of 5.34 GHz at a matching layer thickness of 3.1 mm. In addition, by tailoring the layer thicknesses, the effective absorption frequency bands can be made to cover most of the C, X, and Ku bands. By offering the advantages of stronger absorption, broad absorption bandwidth, low loading, thin layers, and intrinsic light weight, yolk-shell Fe 3 O 4 @N-doped carbon nanochains will be excellent candidates for practical application to microwave absorption. An analysis of the microwave absorption mechanism reveals that the excellent microwave absorption performance can be explained by the quarter-wavelength cancellation theory, good impedance matching, intense conductive loss, multiple reflections and scatterings, dielectric loss, magnetic loss, and microwave plasma loss.

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Section: Emu/g) the Fe 3 O 4 @ N-doped Carbon Nanochains Possess A Hmentioning

confidence: 99%

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

et al. 2018

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“…Each semicircle is associated with one Debye relaxation process. 45 Fig. 7a-c shows the 3 0 -3 00 patterns of the Fe 2 O 3 /N-GN/CNTs, Fe 2 O 3 /N-GN, and Fe 2 O 3 /GN samples.…”

Section: Magnetic Propertiesmentioning

confidence: 99%

Solvothermal synthesis of three-dimensional, Fe₂O₃NPs-embedded CNT/N-doped graphene composites with excellent microwave absorption performance

Zhou

Xiao

et al. 2017

RSC Adv.

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“…According to Debye dipolar relaxation model, 44 the relation of real parts ( ε ′) and imaginary parts ( ε ″) of permittivity can be expressed as the following equation:

{()(, ε^{'} ‐ \frac{ε_{s} + ε_{\infty}}{2})}^{2} + {(ε^{″})}^{2} = {()(, \frac{ε_{s} ‐ ε_{\infty}}{2})}^{2},

where ε s and ε ∞ are the static permittivity and relative dielectric permittivity at the high‐frequency limit, respectively. The curve of ε ′ vs. ε ″ should be a semicircle (Cole‐Cole semicircle) and each semicircle represents one Debye dipolar relaxation process 45 . As shown in Figure 8A, distinct semicircles are presented for the corresponding four samples, demonstrating the existence of Debye dipolar relaxation and good permittivity dissipation capacity.…”

Section: Resultsmentioning

confidence: 90%

Electromagnetic wave absorbing properties of Cr₂AlB₂ powders and the effect of high‐temperature oxidation

et al. 2021

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The electromagnetic (EM) wave absorbing properties of Cr2AlB2 powders and those after high‐temperature oxidation were investigated. Coupling of magnetic and dielectric loss enables Cr2AlB2 with good absorption properties. The minimum reflection loss (RL) value is −44.9 dB at 8.5 GHz with a thickness of 2.7 mm, and the optimized effective absorption bandwidth (EAB) is 4.4 GHz (13.0‐17.4 GHz) with a thickness of 1.6 mm. After oxidation at 750, 900, and 1000°C for 2 h, the minimum RL values, respectively, are −23.9 dB (17.5 GHz, 1.5 mm), −41.4 dB (16.5 GHz, 1.5 mm), and −39.5 dB (8.0 GHz, 3.0 mm); and the corresponding EAB values, respectively, are 3.8 GHz (13.6‐17.4 GHz, 1.7 mm), 4.1 GHz (13.5‐17.6 GHz, 1.6 mm), and 4.4 GHz (13.0‐17.4 GHz, 1.7 mm). With an absorber thickness of 1.5‐4.0 mm, the EAB with a RL value of less than −10 dB can be tuned in a broad‐frequency range 5.0‐18.0 GHz, which basically covers C (4‐8 GHz), X (8‐12 GHz), and Ku (12‐18 GHz) bands. These results demonstrate that Cr2AlB2, as a high‐efficient and oxidation‐resistant absorber, is a promising candidate for microwave absorption applications and can retain good EM wave absorbing properties after high‐temperature oxidation.

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Cole—Cole Diagram and the Distribution of Relaxation Times

Cited by 103 publications

References 6 publications

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

Solvothermal synthesis of three-dimensional, Fe₂O₃NPs-embedded CNT/N-doped graphene composites with excellent microwave absorption performance

Electromagnetic wave absorbing properties of Cr₂AlB₂ powders and the effect of high‐temperature oxidation

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Cole—Cole Diagram and the Distribution of Relaxation Times

Cited by 103 publications

References 6 publications

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

Application of yolk–shell Fe3O4@N-doped carbon nanochains as highly effective microwave-absorption material

Solvothermal synthesis of three-dimensional, Fe2O3NPs-embedded CNT/N-doped graphene composites with excellent microwave absorption performance

Electromagnetic wave absorbing properties of Cr2AlB2 powders and the effect of high‐temperature oxidation

Contact Info

Product

Resources

About

Solvothermal synthesis of three-dimensional, Fe₂O₃NPs-embedded CNT/N-doped graphene composites with excellent microwave absorption performance

Electromagnetic wave absorbing properties of Cr₂AlB₂ powders and the effect of high‐temperature oxidation