Low frequency plasmonic state and negative permittivity spectra of coagulated Cu granular composite materials in the percolation threshold

2013 ◽  
Vol 102 (18) ◽  
pp. 181904 ◽  
Author(s):  
Takanori Tsutaoka ◽  
Teruhiro Kasagi ◽  
Shinichiro Yamamoto ◽  
Kenichi Hatakeyama
Keyword(s):  
Composite Materials ◽  
Percolation Threshold ◽  
Low Frequency ◽  
Negative Permittivity ◽  
Granular Composite

Percolation-induced low frequency plasmonic state in metal granular composite materials

2018 ◽  
Vol 9 (7) ◽  
pp. 476-480
Author(s):  
Takanori Tsutaoka ◽  
Herieta Massango ◽  
Teruhiro Kasagi
Keyword(s):  
Composite Materials ◽  
Low Frequency ◽  
Granular Composite

scholarly journals Communication—Function-Oriented Design of 3D Carbon Networks Toward Negative Permittivity at kHz Frequencies

2022 ◽  
Author(s):  
Yuyan Li ◽  
Huan Ye ◽  
Yunpeng Qu ◽  
Zongxiang Wang ◽  
Kai Sun
Keyword(s):  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Three Dimensional ◽  
Low Frequency ◽  
Calcium Titanate ◽  
Negative Permittivity ◽  
Free Carriers ◽  
Carbon Networks ◽  
Communication Function ◽  
Inductive Character

Abstract Three-dimensional (3D) carbon networks composed of graphene (GR) and carbon nanotube (CNT) were constructed in copper calcium titanate (CCTO) in order to realize negative permittivity behavior. The results show that negative permittivity can be obtained at kHz frequencies above percolation threshold when 3D carbon networks are successfully constructed. Negative permittivity originates from the low-frequency plasmonic state which is explained by the Drude model. The magnitude of negative permittivity was tuned between 105 and 106 which significantly correlates with concentration of free carriers. Moreover, the reactance spectra clarify the inductive character of negative permittivity materials.

Coexistence of gyromagnetic resonance and low frequency plasmonic state in the submicron Ni granular composite materials

2017 ◽  
Vol 121 (10) ◽  
pp. 103902 ◽  
Author(s):  
Herieta Massango ◽  
Takanori Tsutaoka ◽  
Teruhiro Kasagi ◽  
Shinichiro Yamamoto ◽  
Kenichi Hatakeyama
Keyword(s):  
Composite Materials ◽  
Low Frequency ◽  
Granular Composite

Negative permittivity and permeability spectra of Cu/yttrium iron garnet hybrid granular composite materials in the microwave frequency range

2013 ◽  
Vol 103 (26) ◽  
pp. 261906 ◽  
Author(s):  
Takanori Tsutaoka ◽  
Koki Fukuyama ◽  
Hideaki Kinoshita ◽  
Teruhiro Kasagi ◽  
Shinichiro Yamamoto ◽  
...  
Keyword(s):  
Composite Materials ◽  
Yttrium Iron Garnet ◽  
Microwave Frequency ◽  
Negative Permittivity ◽  
Frequency Range ◽  
Yttrium Iron ◽  
Granular Composite ◽  
Permittivity And Permeability ◽  
Iron Garnet

Negative Permittivity Behavior in Silver/Polyaniline Metacomposites Induced by the Low-Frequency Plasmonic Oscillation

2021 ◽  
Author(s):  
Jiahong Tian ◽  
Runhua Fan ◽  
Zongxiang Wang ◽  
Jiahao Xin ◽  
Zhongyang Wang
Keyword(s):  
Synthesis Method ◽  
Low Frequency ◽  
In Situ Synthesis ◽  
Negative Permittivity ◽  
Free Electrons ◽  
Dominant Effect ◽  
Equivalent Circuit Analysis ◽  
Inductive Character ◽  
Percolation Network

Abstract Silver/polyaniline (Ag/PANI) composites were prepared by an in-situ synthesis method. Interestingly, the permittivity changed from positive to negative along with the formation of percolation network. The plasma oscillations of free electrons from the network made a dominant effect on the negative permittivity behavior. Further investigation based on equivalent circuit analysis revealed that the composites with negative permittivity presented inductive character. The epsilon-negative composites can be applied to electromagnetic shielding, absorbing and attenuation.

Enhanced Thermal Conductivity of Composite Materials by Filling Sheet and Fiber Under Effect of Filler Contact

2021 ◽  
Author(s):  
Xiao-jian Wang ◽  
Liang-Bi Wang
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Composite Materials ◽  
Thermal Resistance ◽  
Percolation Threshold ◽  
Filler Content ◽  
Interfacial Thermal Resistance ◽  
Combined Effects ◽  
Enhanced Thermal Conductivity ◽  
The Ideal

Abstract The most common non-granular fillers are sheet and fiber. When they are distributed along the heat flux direction, the thermal conductivity of composite increases greatly. Meanwhile, the filler contact also has large effect on the thermal conductivity. However, the effect of filler contact on the thermal conductivity of composite with directional fillers has not been investigated. In this paper, the combined effects of filler contact, content and orientation are investigated. The results show that the effect of filler orientation on the thermal conductivity is greater than filler contact in low filler content, and exact opposite in high filler content. The effect of filler contact on fibrous and sheet fillers is far greater than cube and sphere fillers. This rule is affected by the filler contact. The filler content of 8% is the ideal percolation threshold of composite with fibrous and sheet filler. It is lower than cube filler and previous reports. The space for thermal conductivity growth of composite with directional filler is still very large. The effect of interfacial thermal resistance should be considered in predicting the thermal conductivity of composite under high Rc (>10-4).

Double negative electromagnetic property of granular composite materials in the microwave range

2015 ◽  
Vol 383 ◽  
pp. 139-143 ◽  
Author(s):  
Takanori Tsutaoka ◽  
Teruhiro Kasagi ◽  
Shinichiro Yamamoto ◽  
Kenichi Hatakeyama
Keyword(s):  
Composite Materials ◽  
Electromagnetic Property ◽  
Microwave Range ◽  
Double Negative ◽  
Granular Composite

Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold

2020 ◽  
Vol 560 ◽  
pp. 125170
Author(s):  
Andrei A. Snarskii ◽  
Mikhail Shamonin ◽  
Pavel Yuskevich ◽  
Dmitry V. Saveliev ◽  
Inna A. Belyaeva
Keyword(s):  
Composite Materials ◽  
Percolation Threshold ◽  
Effective Medium ◽  
Induced Anisotropy ◽  
Effective Medium Model ◽  
Medium Model

scholarly journals Spectral Characteristics of Acoustic Emission in Carbon Fiber-Reinforced Composite Materials Subjected to Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Vladimir L. Shkuratnik ◽  
Petr V. Nikolenko
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Spectral Characteristics ◽  
Spectral Composition ◽  
Low Frequency ◽  
Sharp Change ◽  
Kaiser Effect ◽  
Emission Activity ◽  
The Time Domain

The article is devoted to the investigation of the spectral characteristics of acoustic emission signals that appear under various schemes of composite materials loading. The tests involved samples of composites reinforced with layers sheets of carbon fiber fabric and dispersed carbon fibers. Based on the results of laboratory tests, a comparison is made between the traditional parameters of acoustic emission and the complete spectrograms of the acoustic emission response developed with the use of a special algorithm. The relationship between the emission activity and the change in the spectral composition of emission hits is shown. For example, for some composites, the acoustic emission memory effect (Kaiser effect) manifests itself not only in the time domain but also in the spectral domain in a form of a sharp change in the amplitudes in the frequency range 130/150 kHz. Also, when the samples were loaded according to the Brazilian scheme, the presence of the so-called “inverse” Kaiser effect is observed, in which the memory carrier “remembers” the previously experienced level of tensile stresses and reproduces this information during subsequent unloading. Such effect manifests itself in the form of a sharp change in the amplitudes in the low-frequency region of the spectrum.

Sign in / Sign up

Export Citation Format

Share Document