scholarly journals Mechanisms of electrical polarization of disordered systems based on Al-substituted LiFe-oxospinel

2021 ◽  
Vol 22 (2) ◽  
pp. 336-340
Author(s):  
A.V. Vakalyuk ◽  
V.M. Vakalyuk ◽  
M.I. Hasiuk ◽  
I.M. Hasiuk
Keyword(s):  
Impedance Spectroscopy ◽  
Dielectric Permittivity ◽  
Low Temperatures ◽  
Disordered Systems ◽  
Aluminum Content ◽  
Electric Polarization ◽  
Electrical Polarization ◽  
Temperature Range ◽  
Conductive Properties ◽  
Frequency Dependences

The temperature-frequency dependences of the dielectric  permittivity and conductivity of Li2O-Fe2O3-Al2O3 ceramics in the temperature range of 298-648 K were obtained by impedance spectroscopy. Their analysis indicates the presence of a fractal-like structure in the studied samples, the effect of which is manifested at low temperatures. To study the phenomenon of electric polarization associated with this structure, we used the generalized law of Jonscher. A significant dependence of the dispersion of dielectric and conductive properties of these spinel ceramics on the temperature and aluminum content in them was revealed.

scholarly journals Dielectric properties of Bi12SiO20 crystals doped with Al

2019 ◽  
Vol 27 (2) ◽  
pp. 85-88
Author(s):  
T. V. Panchenko ◽  
L. M. Karpova
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
Hysteresis Loops ◽  
Complex Dielectric Permittivity ◽  
Temperature Range ◽  
Dielectric Matrix ◽  
Before And After ◽  
Frequency Dependences

The temperature-frequency dependences of the complex dielectric permittivity ε and the voltage-farad characteristics of undoped and aluminum doped Bi12SiO20 crystals are studied before and after their polarization. It is shown that Al ions in the Bi12SiO20 dielectric matrix provide a significant increase as well as nonlinearity of ε in the temperature range 300 – 800 K and electric field strengths Е = 103 – 104 V/cm. It is shown that polarization causes the appearance of dielectric hysteresis loops. Al impurity significantly affects the appearance and parameters of these loops. The role of Al ions in increasing the contribution of the quasi-dipole mechanism in the polarization processes is revealed.

Features of radiothermoluminescence of polypropylene and ethylene propylenediene elastomer SKEPT-4044 compositions with nanoscale metal-containing fillers

2020 ◽  
pp. 66-73
Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Molecular Mobility ◽  
Fe3o4 Nanoparticles ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Relaxation Processes ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Β Relaxation

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

Dynamic Viscosity of Compressed Water to 10 Kilobar and Steam to 1500°C

1969 ◽  
Vol 11 (2) ◽  
pp. 189-205 ◽  
Author(s):  
E. A. Bruges ◽  
M. R. Gibson
Keyword(s):  
Gaseous Phase ◽  
Dynamic Viscosity ◽  
Low Temperatures ◽  
Pressure Range ◽  
Low Pressure ◽  
Temperature Range ◽  
Inversion Temperature ◽  
Pressure Steam ◽  
Correlating Equations ◽  
First Time

Equations specifying the dynamic viscosity of compressed water and steam are presented. In the temperature range 0-100cC the location of the inversion locus (mu) is defined for the first time with some precision. The low pressure steam results are re-correlated and a higher inversion temperature is indicated than that previously accepted. From 100 to 600°C values of viscosity are derived up to 3·5 kilobar and between 600 and 1500°C up to 1 kilobar. All the original observations in the gaseous phase have been corrected to a consistent set of densities and deviation plots for all the new correlations are given. Although the equations give values within the tolerances of the International Skeleton Table it is clear that the range and tolerances of the latter could with some advantage be revised to give twice the existing temperature range and over 10 times the existing pressure range at low temperatures. A list of the observations used and their deviations from the correlating equations is available as a separate publication.

Optimization of Sample Holder Materials for Sensitive Magnetometry Measurements at Low Temperatures

2004 ◽  
Vol 825 ◽  
Author(s):  
I. Bossi ◽  
N.R. Dilley ◽  
J. R. O'Brien ◽  
S. Spagna
Keyword(s):  
Magnetic Field ◽  
Low Temperatures ◽  
Magnetic Response ◽  
Sample Holder ◽  
Magnetization Measurements ◽  
Temperature Range ◽  
Paramagnetic Impurities ◽  
Fused Quartz

AbstractMagnetization measurements were performed as a function of magnetic field H and temperature T on samples of nine different materials including clear fused quartz, cartridge brass, G-10 glass-reinforced epoxy, acetal homopolymer, glass-filled acetal, phenolic, and other plastics. A small yet distinct amount of ferromagnetic or paramagnetic impurities is observed in all the materials investigated in this study except quartz. In contrast, the magnetic response of quartz is typical of a diamagnet over the temperature range 5 K to 300 K. The volume susceptibility is equal to −4.4×10−7 (cgs) over the whole temperature range.

Wide-Temperature-Range Dielectric Permittivity Measurement under High Pressure

2017 ◽  
Vol 34 (4) ◽  
pp. 040701
Author(s):  
Zhen Yuan ◽  
Jin-Long Zhu ◽  
Shao-Min Feng ◽  
Chang-Chun Wang ◽  
Li-Juan Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Dielectric Permittivity ◽  
Wide Temperature Range ◽  
Temperature Range ◽  
Permittivity Measurement

Using Atomic Charges to Model Molecular Polarization.

2022 ◽  
Author(s):  
Frank Jensen
Keyword(s):  
Force Fields ◽  
Atomic Charge ◽  
Electric Polarization ◽  
Special Focus ◽  
Atomic Charges ◽  
Electrical Polarization

We review different models for introducing electrical polarization in force fields, with special focus on methods where polarization is modelled at the atomic charge level. While electric polarization has been...

scholarly journals Separating bulk from grain boundary Li ion conductivity in the sol–gel prepared solid electrolyte Li1.5Al0.5Ti1.5(PO4)3

2015 ◽  
Vol 3 (42) ◽  
pp. 21343-21350 ◽  
Author(s):  
Stefan Breuer ◽  
Denise Prutsch ◽  
Qianli Ma ◽  
Viktor Epp ◽  
Florian Preishuber-Pflügl ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
Ion Transport ◽  
Solid Electrolyte ◽  
Transport Properties ◽  
Low Temperatures ◽  
Sol Gel ◽  
Ion Conductivity ◽  
Li Ion ◽  
Ceramic Electrolytes

Impedance spectroscopy measurements down to very low temperatures allowed for resolving bulk ion transport properties in highly conducting ceramic electrolytes.

Electrical Dielectric Permittivity and Conductivity Analysis of Poly(N-Carbazole) (PVK) Blending with Polyvinylpyrrolidone (PVP)

2018 ◽  
Vol 762 ◽  
pp. 244-248
Author(s):  
Ahmad Nazib Alias ◽  
Zubainun Mohamed Zabidi ◽  
N. Ramlee ◽  
Yanti Yaacob ◽  
Siti Hajar Noor Alshurdin ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Dielectric Permittivity ◽  
Ac Conductivity ◽  
Electrochemical Impedance ◽  
Casting Method ◽  
Vacuum Oven ◽  
Correlated Barrier Hopping ◽  
Universal Power Law ◽  
Hopping Model

Electrical dielectric spectra and alternating current (ac) conductivity of blended poly (N-vinlycarbazole) (PVK) with polyvinylpyrrolidone (PVP) at different temperature are investigated. The polymer blends were prepared by dissolving in dimethylformamide (DMF) using drop casting method and further dried in vacuum oven. The dielectric and ac conductivity of each sample was investigated using electrochemical impedance spectroscopy (EIS) method. Dielectric permittivity studies revealed that there are significant changes in the spectra at different temperature. The ac conductivity was further analyzed by using universal power law. The hopping parameter was calculated by using correlated barrier hopping model.

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