scholarly journals Modifying of the dielectric properties of adsorbed water in the force field of a solid surface

2021 ◽  
Vol 1198 (1) ◽  
pp. 012011
Author(s):  
I G Simakov ◽  
Ch Zh Gulgenov ◽  
S B Bazarova
Keyword(s):  
Dielectric Properties ◽  
Force Field ◽  
Solid Surface ◽  
Adsorbed Water ◽  
Surface Force ◽  
Characteristic Size ◽  
Dielectric Relaxation Time ◽  
Debye Relaxation ◽  
Relaxation Theory ◽  
Mobility Of Molecules

Abstract The results of thermodynamic and acoustoelectric studies of changes in the dielectric properties of adsorbed water under the influence of a solid surface force field are presented. It is noted that the dielectric properties of adsorbed water depend not only on the characteristic size of the system, but also on the interaction energy with the solid surface. Near the hydrophilic solid surface, the density of adsorbed water is increased and the mobility of molecules is reduced. The opposite effect occurs for hydrophobic surfaces. The frequency dependences of the dielectric properties of adsorbed water, as in the case of water in the solid and liquid phase, can be characterized using Debye relaxation theory. It is shown that a significant increase in the orientational dielectric relaxation time in adsorbed water can be explained by taking into account the energy of interfacial boundaries.

Dielectric Properties of CaCu3Ti4O12 Ceramics

2010 ◽  
Vol 434-435 ◽  
pp. 253-255
Author(s):  
Jing Han You ◽  
Xiao Yang Gong ◽  
Tong Wei Li ◽  
Qing Dong Chen ◽  
Li Ben Li
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Frequency ◽  
Solid State Reaction Method ◽  
Dielectric Constants ◽  
Debye Relaxation ◽  
Relaxation Theory ◽  
Reaction Method ◽  
Theoretical Results

CaCu3Ti4O12 ceramics were prepared by the traditional solid-state reaction method and the dielectric properties were investigated, the activation energy and relaxation time factor of the samples were calculated. Debye relaxation theory was attempted to analyze the experimental datum, the static and high-frequency dielectric constants were obtained according to Cole-Cole spectra. The temperature dependence of the dielectric constant of CaCu3Ti4O12 were fitted by computer and the theoretical results nearly agree with experimental results.

Electromagnetic Property of MnZn Ferrite/SrTiO3/PTFE Composites

2008 ◽  
Vol 368-372 ◽  
pp. 629-631 ◽  
Author(s):  
Hai Bo Yang ◽  
Ying Lin ◽  
Fen Wang
Keyword(s):  
Heat Treatment ◽  
Electromagnetic Property ◽  
Ferrite Powder ◽  
High Permeability ◽  
Low Loss ◽  
Debye Relaxation ◽  
Relaxation Theory ◽  
Mnzn Ferrite ◽  
Ptfe Composite ◽  
Ptfe Composites

MnZn ferrite powder was modified by SrTiO3 sol and then filled into PTFE matrix to form MnZn ferrite/SrTiO3/PTFE composite. The effect of modification and heat-treatment on the electromagnetic property of the composite was investigated. The results revealed that the as-prepared composite possessed high permeability, high permittivity and low loss. The modification and heat-treatment could improve the electromagnetic property of the composites. The frequency dependence of the dielectric property of the composite is accorded with Debye relaxation theory.

Broadband Dielectric Spectroscopy Analysis of Dielectric Properties of Barium Titanate Ceramics

2013 ◽  
Vol 744 ◽  
pp. 323-328 ◽  
Author(s):  
Jie Yang ◽  
Xiang Yun Deng ◽  
Jian Bao Li ◽  
Qiang Cai ◽  
Hai Tao Zhang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Relaxation Model ◽  
Debye Relaxation ◽  
Broadband Dielectric Spectroscopy ◽  
Function Fitting ◽  
Loss Experience ◽  
Titanate Ceramics

The complex dielectric behaviors of ferroelectric barium titanate (BT) ceramics were investigated. The dielectric properties were studied as a function of temperature and frequency using broadband dielectric spectrometer. The results show that the maximum value of dielectric constant occurs at 500nm BT ceramics, which is approximately 7,500; the dielectric loss is lower than 0.03 with the temperature varying from 225 K to 450 K. Dielectric constant and dielectric loss experience three dielectric peaks corresponding to rhombohedral to orthorhombic, tetragonal and cubic transitions. With the frequency ranges from 1 MHz to 1 GHz, the dielectric relaxation is apparently present. The relaxation process obeys Cole-Cole relaxation model at high temperature and conforms to Debye relaxation model when the temperature far lower than Curie temperature. The relaxation time is the order magnitude of ~10-9s obtained by Havriliak-Negami function fitting, which is very consistent with theoretical calculation.

DIELECTRIC PROPERTIES OF DRY, GEOLOGIC MATERIALS

Geophysics ◽  
1970 ◽  
Vol 35 (4) ◽  
pp. 624-645 ◽  
Author(s):  
M. Saint‐Amant ◽  
David W. Strangway
Keyword(s):  
Dielectric Properties ◽  
Loss Tangent ◽  
Relaxation Times ◽  
Low Frequency ◽  
Frequency Dispersion ◽  
Relaxation Peak ◽  
Debye Relaxation ◽  
Thermally Activated ◽  
Geologic Materials ◽  
Frequency Independent

A detailed investigation of the dielectric properties of powdered and solid dry rocks in the frequency range of 50 hz to 2 mhz has revealed the following general characteristics: 1) All dry rocks, powdered and solid, show an increase in both the dielectric constant and the loss tangent as frequency decreases and as temperature increases. This dispersion is believed to be due to polarization associated with charge buildup at grain boundaries or at grain imperfections. 2) Dry powdered rocks often show a thermally‐activated relaxation peak with a typical Debye‐relaxation character. This is due to the presence of pyroxene and biotite and may be associated with other minerals. The relaxation peak is not seen in solid rocks, where it is hidden by the low‐frequency dispersion. 3) At high frequencies, the loss tangent approaches a constant value which is frequency independent. This behavior is observed in many dielectrics and may be the result of a distribution of relaxation times.

Fractal growth in the presence of a surface force field

2012 ◽  
Vol 85 (5) ◽  
Author(s):  
F. Carlier ◽  
E. Brion ◽  
V. M. Akulin
Keyword(s):  
Force Field ◽  
Surface Force ◽  
Fractal Growth

scholarly journals Structural, Thermal, Electrical and Dielectric Properties of La1-xSrxMn0.50Fe0.50O3 {0.10 ≤ x ≤ 0.40} Cathode Material for Solid Oxide Fuel Cells

2020 ◽  
Vol 32 (12) ◽  
pp. 3165-3172
Author(s):  
Manokamna ◽  
S. Paul ◽  
A. Singh ◽  
K.L. Singh ◽  
A.P. Singh
Keyword(s):  
Fuel Cells ◽  
Dielectric Properties ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Solid State Reaction Method ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Debye Relaxation ◽  
Maximum Conductivity ◽  
Electrical And Dielectric Properties

La1-xSrxMn0.50Fe0.50O3 {0.10 ≤ x ≤ 0.40} perovskite ceramics material is prepared by solid-state reaction method and samples are characterized to study their structural, thermal, electrical and dielectric properties. X-ray diffraction results show that as prepared samples are well crystallized in single phase and have rhombohedral crystal structure. Density is measured by Archimedes principle and with Sr substitution its value decreasing. Thermogravimetric analysis shows the weight gain in the material above 300 ºC. Thermal expansion coefficient value for x = 0.10 and 0.40 composition is found to be 12.9 × 10-6 ºC−1 and 11.3 × 10-6 ºC−1, respectively upto 800 ºC. Impedance analyzer is used to study dielectric and electrical properties which show that all the as prepared samples obey non-Debye relaxation behaviour. The maximum conductivity value is 121.09 S cm-1 for x = 0.10 and 155.96 S cm-1 for x = 0.40 at 600 ºC and 303.59 S cm-1 for x = 0.10 and 362.35 S cm-1 for x = 0.40 at 800 ºC which confirmed that in the experimental perovskite the conductivity increases after Sr doping. Activation energy also found to be decreases with Sr substitution. Therefore, studied properties confirmed that the as-prepared material is a suitable cathode material for intermediate temperature solid oxide fuel cells (SOFCs).

scholarly journals Properties of Water at Solid Surface Revealed Using Surface Force Measurement

2010 ◽  
Vol 59 (11) ◽  
pp. 957-965 ◽  
Author(s):  
Motohiro Kasuya ◽  
Masashi Mizukami ◽  
Kazue Kurihara
Keyword(s):  
Solid Surface ◽  
Force Measurement ◽  
Surface Force
Sign in / Sign up

Export Citation Format

Share Document