Fabrication of Graphene Network in Alumina Ceramics with Adjustable Negative Permittivity by Spark Plasma Sintering

Yin, Rui; Wu, Haikun; Sun, Kai; Li, Xiaomin; Yan, Chao‐Guo; Zhao, Wan‐Lei; Guo, Zhanhu; Qian, Lei

doi:10.1021/acs.jpcc.7b11177

Cited by 36 publications

(13 citation statements)

References 77 publications

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“…Along with the microstructural transformation of the resulting composites, the conductive mechanism of the resulting composites changed from hopping conduction to electron conduction. The similar phenomenon was also observed in percolating ceramic-based composites [4,38] .…”

Section: Resultssupporting

confidence: 81%

Negative permittivity derived from inductive characteristic in the percolating Cu/EP metacomposites

Sun

Xin

et al. 2019

Journal of Materials Science & Technology

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Recently, increasing attention has been concentrated on negative permittivity with the development of the emerging metamaterials composed of periodic array structures. However, taking facile preparation into consideration, it is important to achieve negative permittivity behavior based on materials' intrinsic properties rather than their artificially periodic structures. In this paper, we proposed to fabricate the percolating copper/epoxy resin (Cu/EP) composites by a polymerization method to realize the negative permittivity behavior. When Cu content in the composites reached to 80 wt.%, the conductivity abruptly went up by three orders of magnitudes, suggesting a percolation behavior. Below the percolation threshold, the conductivity spectra conform to Jonscher's power law; when the Cu/EP composites reached to percolating state, the conductivity gradually reduced in 2 high frequency region due to the skin effect. It is indicated that the conductive mechanism changed from hopping conduction to electron conduction. In addition, the permittivity did not increase monotonously with the increase of Cu content in the vicinity of percolation threshold, due to the presence of leakage current. Meanwhile, the negative permittivity conforming to Drude model was observed above the percolation threshold. Further investigation revealed that there was a constitutive relationship between the permittivity and the reactance. When conductive fillers are slightly above the percolation threshold, the inductive characteristic derived from conductive percolating network leads to the negative permittivity. Such epsilon-negative materials can potentially be applied in novel electrical devices, such as high-power microwave filters, stacked capacitors, negative capacitance field effect transistors and coil-free resonators. In addition, the design strategy based on percolating composites provides an approach to epsilon-negative materials.

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Section: Resultssupporting

confidence: 81%

Negative permittivity derived from inductive characteristic in the percolating Cu/EP metacomposites

Sun

Xin

et al. 2019

Journal of Materials Science & Technology

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“…The reaction between the two components should be avoided to ensure the generation of resonance and negative permittivity. [ 102,103 ] For normal resonance in dielectric ceramics, the permittivity can be described by the Lorentz model [ 104 ] :

ε_{r} = 1 + \frac{N q^{2}}{m_{eff} ε_{0}} ∙ \frac{1}{ω_{0}^{2} - ω^{2} + i ω ω_{τ}},

where ω 0 = 2 πf 0 is the characteristic frequency, m eff is the effective mass of the carrier, N is the number of charges per unit volume, q is the charge of the carrier, ω is the angular frequency, and ω τ is the collision frequency. With the introduction of conductive metals, the effective permittivity can be modified, leading to a dilution of the effective electron concentration.…”

Section: Natural Ceramic Materials Inspired By Metamaterialsmentioning

confidence: 99%

“…The reaction between the two components should be avoided to ensure the generation of resonance and negative permittivity. [102,103] For normal resonance in dielectric ceramics, the permittivity can be described by the Lorentz model [104] :…”

Section: Natural Ceramic Materials Inspired By Metamaterialsmentioning

confidence: 99%

Ceramic‐based dielectric metamaterials

Luo

Yan

Zhou

2022

Interdisciplinary Materials

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Dielectric metamaterials based on ceramics have attracted considerable interest in the past few years owing to their low dielectric loss, simple structure, excellent multifield tunability, and good environmental adaptability. They are considered to be promising alternative to metal‐based metamaterials and can lead to a new strategy for the development of passive devices. In this review, the recent progress of ceramic‐based dielectric metamaterials in electromagnetic applications, energy applications, non‐Hermitian systems, and natural materials with near‐zero or negative refraction are summarized. The design principle and mechanism, as well as manufacturing technologies, are also introduced, and the current development trend of ceramic‐based dielectric metamaterials are proposed.

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“…Despite the negative permittivity fitted with the Lorentz model, the negative permittivity (-75 to -25) over the whole frequency in FGR98 was consistent with the fitted results from the Drude model. Yin et al 64 achieved the negative permittivity from the graphenealumina (GR-Al 2 O 3 ) composites which were prepared by the spark plasma sintering method. A plasma-like negative permittivity (Figure 3a) was achieved when GR content reached 15.38 and 18.64 wt%, attributing to the fabrication of continuous GR networks (Figure 3c and d).…”

Section: Metacomposites With Gr As Fillersmentioning

confidence: 99%

Recent Progress on the Metacomposites with Carbonaceous Fillers

Wu¹,

Huang²,

Qian³

2020

Eng. Sci.

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Different from common "Metamaterials", "Metacomposites" are used to describe random nanocomposites with negative permittivity, which is determined by controlling their microstructures and compositions. Metacomposites with unique negative permittivity show potential applications in superconductors, wave filters, capacitors, electromagnetic interference shielding or absorbing and other fields. In this review, Drude model, Lorentz model and "double nano wires" model used to analyze negative permittivity were discussed. Preparation, properties and mechanism of negative permittivity from metacomposites in corporation of carbon nanomaterials as fillers were reviewed and analyzed. Besides, the applications of metacomposites in the field of electromagnetic wave absorption and improving the performance of the antenna were also discussed.

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Fabrication of Graphene Network in Alumina Ceramics with Adjustable Negative Permittivity by Spark Plasma Sintering

Cited by 36 publications

References 77 publications

Negative permittivity derived from inductive characteristic in the percolating Cu/EP metacomposites

Negative permittivity derived from inductive characteristic in the percolating Cu/EP metacomposites

Ceramic‐based dielectric metamaterials

Recent Progress on the Metacomposites with Carbonaceous Fillers

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