Modeling of Spatially-Dispersive Wire Media: Transport Representation, Comparison With Natural Materials, and Additional Boundary Conditions

Here a method for estimating the effective parameters (effective conductivity) of spherical aerogels of multilayer carbon nanotubes (CNTs) is proposed using the measured values of their polarizability and the wire medium model. While aerogels have a structure formed with tangles of curved nanotubes with chaotic contact distribution, the possibility to describe their electrophysical properties using the regular connected wire medium is estimated here. Calculations of the polarizability of regular structures consisting of copper and CNT wires of identical diameters (not less than 50 nm) for different models are performed. It is suggested that by selecting the parameters of a regular medium, it is possible to achieve the closeness of the polarizability values of samples of the same shape consisting of regular and irregular media. The calculated polarizability values of aerogels are consistent with the results of measurements of polarizability performed using the method of open resonators in the range 8–12 GHz. The possibility of estimating the electrophysical characteristics of carbon aerogels is considered for further modeling of the electromagnetic characteristics of composites based on them.

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“…The term

\frac{σ}{ϵ D} = k_{normalD}^{2}

is the Debye wave number, and

l_{normalD} = \frac{1}{k_{normalD}}

is the Debye length (the screening radius). The diffusion coefficient for a wire medium is given in

D = \frac{i ω}{l_{0} true[\frac{β_{normalp}^{2}}{ϵ_{normalm} - 1} \frac{1}{f_{normalV}} - \frac{ω^{2}}{c^{2}} true]}

…”

Section: Polarizability Models Of Wire Spherical Objectsmentioning

confidence: 99%

The Usage of Conducting Wire Sphere Models for the Estimation of Electrophysical Properties of Multiwalled Carbon Nanotube Spherical Aerogels

Dorofeev

Suslyaev

Karzanova

et al. 2018

Physica Status Solidi (b)

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“…In an earlier study, [29] we have used the regular wire medium model [20,32,33] as a structural model of the MWCNT aerogel medium. The main assumption of this approach is that the electrophysical parameters of an irregular medium (aerogel) will be equivalent to the parameters of a regular medium for some effective lattice constant of this regular medium.…”

Section: Introductionmentioning

confidence: 99%

Interaction of Multiwalled Carbon Nanotube Aerogels with Quasi‐Optical Terahertz Beams

Dorofeev

Suslyaev

Мосеенков

et al. 2019

Physica Status Solidi (b)

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This article presents the measurements of the reflectance from a plane‐parallel aerogel sample formed by multiwalled carbon nanotubes (MWCNTs) in the terahertz range. With an increase in frequency from 100 GHz to 1.5 THz, the reflectance decreases by more than a factor of two. Based on the experimental data and the well‐known wire medium model formed by a three‐dimensional lattice of intersecting conductors, a model of a regular wire medium is constructed using MWCNTs with effective electrophysical characteristics equivalent to those of an irregular aerogel medium. This model reveals that a significant drop in the reflectance in the terahertz frequency range occurs because the plasma frequency of the equivalent medium is located here. The model allows estimating the properties of the aerogel environment in the frequency range extending up to 5 THz and with variations in the packing density of MWCNTs in aerogel. Estimates of the reflection, transmission, and absorption are presented for the case of normal incidence on a thin (submillimeter) layer of such a medium. The aerogel absorption at a given conductivity of CNTs is determined by their packing density.

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“…1. As a result, a rigorous study of such metamaterials was then undertaken by Silveirinha et al [18][19][20][21][22][23][24][25][26] This team accurately derived analytical models, using additional boundary conditions and/or quasistatic approximations, to eliminate the additional degree of freedom due to spatial dispersion.…”

Section: Introductionmentioning

confidence: 99%

Dispersion effects in Fakir's bed of nails metamaterial waveguides

Papantonis

Lucyszyn

Shamonina

2014

Journal of Applied Physics

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Articles you may be interested inEffects of inductive waves on multi-band below-cut-off transmission in waveguides loaded with dielectric metamaterials AIP Advances 4, 107129 (2014); 10.1063/1.4898706 Review Article: The weak interactive characteristic of resonance cells and broadband effect of metamaterials AIP Advances 4, 100701 (2014); 10.1063/1.4897915 Volumetric negative-refractive-index metamaterials based upon the shunt-node transmission-line configuration Experimental verification of backward-wave radiation from a negative refractive index metamaterialThe propagation characteristics of electromagnetic waves in waveguides implemented using the "Fakir's bed of nails" are investigated both analytically and numerically. The classical metal walls of a parallel-plate waveguide are replaced by a Fakir's bed of nails metamaterial having arbitrary pin lengths on both walls; treated as a homogenized effective spatially dispersive dielectric. A modal analysis of the electromagnetic fields is presented for the first time, and dispersion expressions for the propagating modes are derived analytically and independently validated with full-wave numerical simulations. An equivalent transmission line model is also given, and similarities with the classical metal-dielectric-metal structure commonly used in optics are discussed. V C 2014 AIP Publishing LLC. [http://dx.

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Modeling of Spatially-Dispersive Wire Media: Transport Representation, Comparison With Natural Materials, and Additional Boundary Conditions

Cited by 34 publications

References 34 publications

The Usage of Conducting Wire Sphere Models for the Estimation of Electrophysical Properties of Multiwalled Carbon Nanotube Spherical Aerogels

The Usage of Conducting Wire Sphere Models for the Estimation of Electrophysical Properties of Multiwalled Carbon Nanotube Spherical Aerogels

Interaction of Multiwalled Carbon Nanotube Aerogels with Quasi‐Optical Terahertz Beams

Dispersion effects in Fakir's bed of nails metamaterial waveguides

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