Tailorable epsilon-negative and epsilon-near-zero behavior of TiC/CCTO metacomposites: Low-frequency plasma oscillation

2021 ◽  
pp. 2150015
Author(s):  
Baogang Ding ◽  
Yunpeng Qu ◽  
Kai Sun ◽  
Runhua Fan
Keyword(s):  
Plasma Oscillation ◽  
Three Dimensional ◽  
Low Frequency ◽  
Calcium Titanate ◽  
Negative Permittivity ◽  
Free Electrons ◽  
Frequency Plasma ◽  
Collective Plasma ◽  
Negative Formula ◽  
Epsilon Near Zero

Epsilon-negative ([Formula: see text]) and epsilon-near-zero (ENZ) property was demonstrated in titanium carbide/copper calcium titanate (TiC/CCTO) metacomposites. Benefiting from the moderate concentration of free electrons in TiC filler and its adjustable three-dimensional (3D) networks, weakly negative permittivity ([Formula: see text]200 at 20 MHz) was achieved. Not only that, tailoring the negative permittivity of metacomposites from [Formula: see text]200 to [Formula: see text]2060, [Formula: see text]4200, [Formula: see text]14000 and [Formula: see text]70000 at 20 MHz was realized by simply increasing TiC content. Besides, Drude model was used to explain the radio-frequency (RF) negative permittivity and quantified the collective plasma oscillation in TiC networks.

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.

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.

Complex Permittivity and Permeability Spectra of Nickel/Polyphenylene Sulfide Composite in Radio Frequency Range

2017 ◽  
Vol 898 ◽  
pp. 1757-1763
Author(s):  
Guo Hua Fan ◽  
Run Hua Fan ◽  
Zhong Yang Wang ◽  
Pei Tao Xie ◽  
Min Chen ◽  
...  
Keyword(s):  
High Frequency ◽  
Conduction Mechanism ◽  
Plasma Oscillation ◽  
Polyphenylene Sulfide ◽  
Negative Permittivity ◽  
Electromagnetic Properties ◽  
Double Negative ◽  
Frequency Range ◽  
Free Electrons ◽  
Negative Materials

Due to the distinct electromagnetic properties, double negative materials have bright application prospect in many areas in the future. The nickel (Ni)/polyphenylene sulfide (PPS) composites were prepared by hot pressing Ni and PPS powders mixture. Microstructures, dielectric properties, and magnetic performances of the resulted composites were studied in detail. Once Ni contents exceeded the percolation threshold, the conductive networks would form and the conduction mechanism would change from hopping conduction to metal-like conduction. Due to the plasma oscillation of the free electrons within the conductive networks, negative permittivity appeared. Interestingly, circuit loops in the connected Ni particles induced by external electric field resulted in a diamagnetic phenomenon under high frequency for the composite with ferromagnetic Ni particles.

Energy‐loss rate and enhanced diffusion due to a low‐frequency plasma oscillation

1986 ◽  
Vol 60 (10) ◽  
pp. 3422-3426 ◽  
Author(s):  
Alexander J. Anastassiades ◽  
Efstathios G. Sideris
Keyword(s):  
Energy Loss ◽  
Loss Rate ◽  
Plasma Oscillation ◽  
Low Frequency ◽  
Enhanced Diffusion ◽  
Energy Loss Rate ◽  
Frequency Plasma

scholarly journals Communication—Tunable Negative Permittivity of Cobalt and Epoxy Composites at 3 kHz ~ 1 MHz Frequency Regions

2021 ◽  
Author(s):  
Min Chen ◽  
Kai Sun ◽  
Xuai Wang ◽  
Yanmin Wang
Keyword(s):  
Potential Application ◽  
Low Frequency ◽  
Negative Permittivity ◽  
Epoxy Composites ◽  
Conductive Network ◽  
Free Electrons ◽  
Metal Composites ◽  
Large Numbers

Abstract Negative permittivity in percolation composites has drawn much attention owing to their potential application. This study set out to explore whether tunable negative permittivity can be realized in metal composites at 3 kHz ~ 1 MHz frequency regions. When the content of cobalt is 80 wt%, the permittivity turns to negative in the test band. These findings show that the Co conductive network has formed and provides large numbers of free electrons. Meanwhile, the percolation composites with negative permittivity show inductive characteristic. This research supports the idea that tunable low-frequency negative permittivity can be realized in metal composites.

scholarly journals Recovering the Damping Rates of Cyclotron Damped Plasma Waves from Simulation Data

2017 ◽  
Vol 21 (4) ◽  
pp. 947-980 ◽  
Author(s):  
Cedric Schreiner ◽  
Patrick Kilian ◽  
Felix Spanier
Keyword(s):  
Three Dimensional ◽  
Low Frequency ◽  
Plasma Waves ◽  
Simulation Data ◽  
Simple Method ◽  
Particle In Cell ◽  
Frequency Plasma ◽  
Damping Rate ◽  
Theoretical Predictions ◽  
Dimensional Simulation

AbstractPlasma waves with frequencies close to the particular gyrofrequencies of the charged particles in the plasma lose energy due to cyclotron damping. We briefly discuss the gyro-resonance of low frequency plasma waves and ions particularly with regard to particle-in-cell (PiC) simulations. A setup is outlined which uses artificially excited waves in the damped regime of the wave mode's dispersion relation to track the damping of the wave's electromagnetic fields. Extracting the damping rate directly fromthe field data in real or Fourier space is an intricate and non-trivial task. We therefore present a simple method of obtaining the damping rate Γ from the simulation data. This method is described in detail, focusing on a step-by-step explanation of the course of actions. In a first application to a test simulation we find that the damping rates obtained from this simulation generally are in good agreement with theoretical predictions. We then compare the results of one-, two- and three-dimensional simulation setups and simulations with different physical parameter sets.

scholarly journals Evolution of a narrow-band spectrum of random surface gravity waves

2003 ◽  
Vol 478 ◽  
pp. 1-10 ◽  
Author(s):  
KRISTIAN B. DYSTHE ◽  
KARSTEN TRULSEN ◽  
HARALD E. KROGSTAD ◽  
HERVÉ SOCQUET-JUGLARD
Keyword(s):  
Three Dimensional ◽  
Low Frequency ◽  
Three Dimensions ◽  
Band Spectrum ◽  
Nls Equation ◽  
Random Surface ◽  
Narrow Bandwidth ◽  
Quasi Stationary State ◽  
The Stability ◽  
Three Dimensional Simulations

Numerical simulations of the evolution of gravity wave spectra of fairly narrow bandwidth have been performed both for two and three dimensions. Simulations using the nonlinear Schrödinger (NLS) equation approximately verify the stability criteria of Alber (1978) in the two-dimensional but not in the three-dimensional case. Using a modified NLS equation (Trulsen et al. 2000) the spectra ‘relax’ towards a quasi-stationary state on a timescale (ε2ω0)−1. In this state the low-frequency face is steepened and the spectral peak is downshifted. The three-dimensional simulations show a power-law behaviour ω−4 on the high-frequency side of the (angularly integrated) spectrum.

The Properties Of a-Si:H/c-Si Heterostructures Prepared By 55 kHz Pecvd For Solar Cell Application

1997 ◽  
Vol 485 ◽  
Author(s):  
B. G Budaguan ◽  
A. A. Aivazov ◽  
A. A. Sherchenkov ◽  
A. V Blrjukov ◽  
V. D. Chernomordic ◽  
...  
Keyword(s):  
Crystalline Silicon ◽  
Low Frequency ◽  
Reverse Current ◽  
Chemical Vapor ◽  
Interface State ◽  
State Density ◽  
Solar Cell Application ◽  
Current Voltage ◽  
Frequency Plasma ◽  
Device Applications

AbstractIn this work a-Si:H/c-Si heterostructures with good electronic properties of a-Si:H were prepared by 55 kHz Plasma Enhanced Chemical Vapor Deposition (PECVD). Currentvoltage and capacitance-voltage characteristics of a-Si:H/c-Si heterostructures were measuredto investigate the influence of low frequency plasma on the growing film and amorphous silicon/crystalline silicon boundary. It was established that the interface state density is low enough for device applications (<2.1010 cm−2). The current voltage measurements suggest that, when forward biased, space-charge-limited current determines the transport mechanism in a- Si:H/c-Si heterostructures, while reverse current is ascribed to the generation current in a-Si:H and c-Si depletion layers.

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