Investigations on frequency and temperature dependence of AC conductivity and dielectric parameters in Ge20Ga5Sb10S65 quaternary chalcogenide glass

Optik ◽  
2019 ◽  
Vol 182 ◽  
pp. 1244-1251 ◽  
Author(s):  
P.N. Musfir ◽  
S. Mathew ◽  
V.P.N Nampoori ◽  
Sheenu Thomas
Keyword(s):  
Temperature Dependence ◽  
Chalcogenide Glass ◽  
Ac Conductivity ◽  
Dielectric Parameters

Electrical and Dielectric Spectroscopic Characterization of Polycrystalline Dy2Si2O7

2012 ◽  
Vol 510-511 ◽  
pp. 194-200 ◽  
Author(s):  
Shahid Ameer ◽  
Asghari Maqsood
Keyword(s):  
High Temperature ◽  
Electrical Transport ◽  
Ac Conductivity ◽  
Orthorhombic Phase ◽  
Theoretical Models ◽  
Spectroscopic Characterization ◽  
Dielectric Parameters ◽  
Triclinic Phase ◽  
Electrical Conductivities ◽  
Phase Type

The compound Dy2Si2O7exists in two polymorphs, the low temperature triclinic phase (type B) and a high temperature orthorhombic phase (type E).The dc and ac electrical conductivities of E-Dy2Si2O7are measured in the temperature range 290-510 K and frequency range 1 kHz to 1 MHz . The dc electrical transport data are analyzed according to Motts variable-range hopping model. The disorder parameter (To) and density of states at fermi level are obtained. The ac conductivity σac(ω) is obtained through the dielectric parameters. The ac conductivity can be expressed as σac(ω) =B ωs, where s is slope and it decreases with increase in temperature. The conduction mechanism in the compound is discussed in low and high temperature regions in the light of theoretical models.

Temperature dependence of Bragg gratings in As2S3 amorphous chalcogenide glass waveguides

2000 ◽  
Author(s):  
Ali Salimmia ◽  
Tigran Galstian ◽  
Alain Villeneuve ◽  
Sophie LaRochelle ◽  
Kathleen Richardson
Keyword(s):  
Temperature Dependence ◽  
Chalcogenide Glass ◽  
Bragg Gratings ◽  
Amorphous Chalcogenide ◽  
Glass Waveguides

Temperature dependence of the dielectric parameters of nonstoichiometric SrTiO3 single crystals

2004 ◽  
Vol 49 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Ya. Doichilovich ◽  
N. Kulagin ◽  
D. Popovich ◽  
S. Spasovich
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Dielectric Parameters

Admittance and Photoadmittance Spectroscopy of Zinc Oxide Layers Grown on p-Si Substrates by Spin Coating Method

2013 ◽  
Vol 200 ◽  
pp. 27-32
Author(s):  
Pawel Popielarski ◽  
Waclaw Bala ◽  
Kazimierz Paprocki
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Dielectric Response ◽  
Ac Conductivity ◽  
Signal Amplitude ◽  
Zno Thin Films ◽  
Si Substrates ◽  
Universal Power Law ◽  
Coating Method ◽  
Different Temperatures

In this work, the dielectric response of ZnO thin films has been studied over a temperature range of 200 K - 550 K. The dielectric response of polycrystalline ZnO thin films in the frequency domain was measured from 42 Hz - to 5 MHz with a small AC signal amplitude at different temperatures. Influence of the light on conductivity has been also investigated. A universal power law relation was brought into picture to explain the frequency dependence of AC conductivity. The temperature dependence of AC conductivity was analyzed in detail. The activation energy obtained from the temperature dependence of AC conductivity was attributed to the shallow trap-controlled space charge conduction in the bulk of the sample.

Temperature dependent dielectric spectroscopy of muscle tissue phantom

2020 ◽  
Vol 12 (9) ◽  
pp. 885-891
Author(s):  
Ondrej Fiser ◽  
Sebastian Ley ◽  
Marko Helbig ◽  
Jürgen Sachs ◽  
Michaela Kantova ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Muscle Tissue ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Dielectric Parameters ◽  
Temperature Range ◽  
Non Invasive ◽  
Tissue Phantom ◽  
Cole Model ◽  
Polyethylene Powder

AbstractThe temperature dependence of the dielectric parameters of tissues and tissue-mimicking phantoms is very important for non-invasive temperature measurement in medical applications using microwaves. We performed measurements of this dependence in the temperature range of 25–50°C using distilled water as a reference liquid commonly used in dielectric property studies. The results were compared with the literature model in the frequency range of 150–3000 MHz. Using this method, the temperature dependence of dielectric parameters of a new muscle tissue-mimicking phantom based on agar, polyethylene powder, and polysaccharide material TX-151 was measured in the temperature range of 25–50°C. The temperature dependence of the dielectric properties of this new muscle phantom was fitted to that of the two-pole Cole–Cole model and the deviation of the results between measured and modeled data was quantified.

AC conductivity and dielectric relaxation of Se80−xTe20Bix (x=6, 12) glasses

2019 ◽  
Vol 60 (6) ◽  
pp. 222-230
Author(s):  
Deepika Deepika ◽  
Hukum Singh
Keyword(s):  
Dielectric Relaxation ◽  
Ac Conductivity ◽  
Lower Energy ◽  
Dielectric Relaxation Time ◽  
Frequency Exponent ◽  
Dielectric Parameters ◽  
Cbh Model ◽  
Increase With Increase ◽  
Different Temperatures ◽  
Frequency Temperature

The present paper reports the ac conductivity and dielectric relaxation of Se80−xTe20Bix (x=6, 12) glasses at various temperatures and frequencies. It was found that ac conductivity increases on increase of frequency, temperature as well as Bi content. The increase in conductivity is due to the formation of lower energy Se–Bi and Te–Bi bonds which takes the system to a stable lower energy configuration. The values of frequency exponent (s) were calculated and it was found that samples obey CBH model of conduction. Density of states (N(Ef)) near the fermi level were calculated at different temperatures and it was found that addition of Bi increases the number of localised states in the tails which leads to increase in ac conductivity. Further, it was found that dielectric parameters increase with increase in temperature. However, a decrease in both dielectric constant (ε′) and dielectric loss ((ε″) was observed with increase in frequency. Beside this, dielectric relaxation time (τ) and activation energy of relaxation (∆Eτ) were also determined for both the samples under study and was found to be lower for Se68Te20Bi12 glass.

Structural and Dielectric Properties of Zn1-xMoxO Nanoparticles

2020 ◽  
Vol 13 (2) ◽  
pp. 165-170
Keyword(s):  
Zinc Oxide ◽  
Dielectric Properties ◽  
Ac Conductivity ◽  
Hexagonal Wurtzite Structure ◽  
Dielectric Constants ◽  
Precipitation Method ◽  
Dielectric Parameters ◽  
Mo Doping ◽  
Lcr Meter ◽  
Co Precipitation

Abstract: In this work, samples of zinc oxide nanoparticles doped by molybdenum (Zn1-xMoxO with 0 ≤ x ≤ 0.1) were prepared by using the wet co-precipitation method. The characterization of the prepared samples was carried out by means of X-ray powder diffraction (XRD). The samples reserved their hexagonal wurtzite structure with Mo doping and showed a decrease in the crystallite size up to x = 0.04 followed by a further increase. On the other hand, dielectric measurements were performed using an LCR meter. The effect of frequency and temperature on the dielectric properties such as the real and imaginary parts of dielectric constant (ε^' and ε'', respectively), dielectric loss (tanδ) and ac-conductivity (σ_ac) of Mo-doped zinc oxide samples, was studied in the frequency range (100 Hz - 1 MHz) and at temperatures (300 - 773 K). The values of room temperature dielectric parameters were found to be strongly dependent on the Mo-doping. However, the increase in temperature caused an enhancement in the values of the dielectric parameters, particularly at 773 K. Keywords: Zinc oxide, XRD, Dielectric constants, Ac-conductivity.

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