scholarly journals Effects of Maxwell-Wagner polarization on soil complex dielectric permittivity under variable temperature and electrical conductivity

2006 ◽  
Vol 42 (6) ◽  
Author(s):  
Yongping Chen ◽  
Dani Or
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Variable Temperature ◽  
Complex Dielectric Permittivity ◽  
Soil Complex

Complex dielectric permittivity, electric modulus and electrical conductivity analysis of Au/Si3N4/p-GaAs (MOS) capacitor

2021 ◽  
Author(s):  
Sema Türkay ◽  
Adem Tataroğlu
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Electric Modulus ◽  
Arrhenius Equation ◽  
Rf Magnetron Sputtering ◽  
Oxide Semiconductor ◽  
Complex Dielectric Permittivity ◽  
Mos Capacitor ◽  
Universal Power Law ◽  
Complex Electrical Conductivity

AbstractRF magnetron sputtering was used to grow silicon nitride (Si3N4) thin film on GaAs substrate to form metal–oxide–semiconductor (MOS) capacitor. Complex dielectric permittivity (ε*), complex electric modulus (M*) and complex electrical conductivity (σ*) of the prepared Au/Si3N4/p-GaAs (MOS) capacitor were studied in detail. These parameters were calculated using admittance measurements performed in the range of 150 K-350 K and 50 kHz-1 MHz. It is found that the dielectric constant (ε′) and dielectric loss (ε″) value decrease with increasing frequency. However, as the temperature increases, the ε′ and ε″ increased. Ac conductivity (σac) was increased with increasing both temperature and frequency. The activation energy (Ea) was determined by Arrhenius equation. Besides, the frequency dependence of σac was analyzed by Jonscher’s universal power law (σac = Aωs). Thus, the value of the frequency exponent (s) were determined.

Wideband Characterization of Soil Complex Dielectric Permittivity Spectrum

2020 ◽  
Author(s):  
Agnieszka Szyplowska ◽  
Hironobu Saito ◽  
Shin Yagihara ◽  
Minoru Fukuzaki ◽  
Kahori Furuhata ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Complex Dielectric Permittivity ◽  
Soil Complex ◽  
Permittivity Spectrum

Combined vector network analyzer and impedance analyzer for broadband determination of complex permittivity spectrum of glass beads with talc

2020 ◽  
Author(s):  
Justyna Szerement ◽  
Hironobu Saito ◽  
Kahori Furuhata ◽  
Shin Yagihara ◽  
Agnieszka Szypłowska ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Dielectric Permittivity ◽  
Glass Beads ◽  
Vector Network Analyzer ◽  
Complex Dielectric Permittivity ◽  
Network Analyzer ◽  
Frequency Range ◽  
Impedance Analyzer ◽  
Permittivity Spectrum

<p>Soil complex dielectric permittivity is frequency dependent. At low frequencies soil dielectric spectrum exhibits relaxation effects mainly due to interfacial phenomena caused by water strongly bounded to solid phase particles surfaces, double-layer effects and Maxwell-Wagner effect. At frequencies of several GHz and above, the influence of dielectric dispersion of free water dipoles can be observed.  Since dielectric soil moisture meters operate at frequencies from kHz up to several GHz, their output can be affected by these phenomena.</p><p>Currently, there is a variety of commercial sensors that operate at various frequencies from kHz up to several GHz. Most popular are TDR sensors with frequency band up to 1-2 GHz and capacitance/impedance sensors that operate at a single frequency usually from the range <br>1-150 MHz. Therefore, the knowledge of the broadband complex dielectric permittivity spectrum can help to improve the existing and develop new methods and devices for soil moisture and salinity estimation. Also, accurate characterization of complex dielectric permittivity spectrum of porous materials in the broadband frequency range is required for modeling of dielectric properties of materials in terms of moisture, salinity, density, mineralogy etc.</p><p>The aim of the study was to measure the complex dielectric permittivity of glass beads with 5% talc moistened with distilled water and saline water (electrical conductivity of 500, 1000, 1500 mS/m). The experiment was carried out using a seven-rod probe connected to an impedance analyzer (IA) and a vector network analyzer (VNA) using a multiplexer in the frequency range from 40Hz to 110MHz (IA) and 10MHz to 500MHz (VNA). The glass beads (90-106 µm, Fuji Manufacturing Industries, Japan) with 5% talc (Sigma Aldrich) in 4 different moisture and 4 different salinity values were examined. The results obtained from the IA and the VNA were combined and modeled with complex conductivity and dielectric permittivity model. The influence of water content and electrical conductivity on broadband complex dielectric spectra and the fitted model parameters was examined.</p><p> </p><p>The work has been supported by the National Centre for Research and Development, Poland, BIOSTRATEG3/343547/8/NCBR/2017.</p>

Soil Complex Dielectric Permittivity Spectra Determination Using Electrical Signal Reflections in Probes of Various Lengths

2016 ◽  
Vol 15 (3) ◽  
pp. vzj2015.10.0135 ◽  
Author(s):  
Agnieszka Szypłowska ◽  
Andrzej Wilczek ◽  
Marcin Kafarski ◽  
Wojciech Skierucha
Keyword(s):  
Dielectric Permittivity ◽  
Electrical Signal ◽  
Complex Dielectric Permittivity ◽  
Soil Complex

Effects of layered sediments on the guided wave in crosswell radar data

Geophysics ◽  
1999 ◽  
Vol 64 (6) ◽  
pp. 1698-1707 ◽  
Author(s):  
Karl J. Ellefsen
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Radar Data ◽  
Guided Wave ◽  
Sand Layer ◽  
Clay Layers ◽  
The Waves

To understand how layered sediments affect the guided wave in crosswell radar data, traces are calculated for a model representing a sand layer between two clay layers. A guided wave propagates if the wavelengths in the sand layer are similar to the thickness of the sand layer. The amplitude of the guided wave but not its initial traveltime is affected by the thickness of the sand layer. In contrast, both the amplitude and the initial traveltime are affected by the locations of the transmitting and receiving antennas, the electrical conductivity of the sand layer, and the dielectric permittivity of the sand layer. This permittivity can be estimated from the initial traveltime. The effects of the layering on the waves in these calculated traces also are observed in field traces, which were collected in layered sediments.

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