The Measurement of Dielectric Constants by the Comparison Method. The Dielectric Constant of Carbon Tetrachloride from 15 to 40°

1942 ◽  
Vol 64 (1) ◽  
pp. 117-121 ◽  
Author(s):  
John G. Miller
Keyword(s):  
Dielectric Constant ◽  
Carbon Tetrachloride ◽  
Comparison Method ◽  
Dielectric Constants

The effects of pressure on the density, dielectric constant, and viscosity of several hydrocarbons and other organic liquids

1969 ◽  
Vol 47 (6) ◽  
pp. 893-899 ◽  
Author(s):  
D. W. Brazier ◽  
G. R. Freeman
Keyword(s):  
Molecular Structure ◽  
Dielectric Constant ◽  
Carbon Tetrachloride ◽  
Pressure Range ◽  
High Pressures ◽  
Liquid Structure ◽  
Dielectric Constants ◽  
Pressure Effects ◽  
Organic Liquids ◽  
Increasing Temperature

The effects of pressures up to 4 kbar on the density, dielectric constant, and viscosity of n-pentane, n-hexane, n-octane, cyclopentane, methylcyclohexane, and 2,2-dimethylbutane (DMB) were measured at 30 °C. The pressure effects on the viscosities of n-hexane and n-octane were also determined at 0 and 60°. The densities of diethyl ether and cyclopentanone and the dielectric constant of carbon tetrachloride at high pressures are also recorded. The densities of the hydrocarbons increased by 20–30% and the dielectric constants increased by 11–16% as the pressure was increased from 1 to 4000 bars at 30°, but the viscosities increased by 695–2352% over the same pressure range. Carbon tetrachloride froze at 1500 bars at 30°, and cyclopentanone froze at 3500 bars at about 20°. In agreement with earlier work on other liquids, the value of the Clausius–Mosotti function (ε − 1)V/(ε + 2) for the present compounds decreased slightly with increasing pressure. The viscosity at a given pressure decreased slightly with increasing temperature, and temperature effect increased with increasing pressure. In general, the smaller the compressibility of the liquid, the greater was the effect of pressure on the viscosity; DMB was an exception because its viscosity increased abnormally rapidly with pressure. Molecular structure and liquid structure have greater influences on the pressure dependence of viscosity than on that of density or dielectric constant.

scholarly journals Comment on “investigation of dielectric constants of water in a nano-confined pore” by H. Zhu, F. Yang, Y. Zhu, A. Li, W. He, J. Huang and G. Li, RSC Adv., 2020, 10, 8628

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 5179-5181
Author(s):  
Sayantan Mondal ◽  
Biman Bagchi
Keyword(s):  
Dielectric Constant ◽  
Dielectric Constants ◽  
Static Dielectric Constant ◽  
Inherent Anisotropy ◽  
Nanoconfined Water

Neglects of inherent anisotropy and distinct dielectric boundaries may lead to completely erroneous results. We demonstrate that such mistakes can give rise to gross underestimation of the static dielectric constant of cylindrically nanoconfined water.

DIELECTRIC CONSTANT AND SEEBECK COEFFICIENT FOR SEMICONDUCTORS: THERMODYNAMIC AND DFT STUDIES

2013 ◽  
Vol 12 (06) ◽  
pp. 1350057 ◽  
Author(s):  
HSIU-YA TASI ◽  
CHAOYUAN ZHU
Keyword(s):  
Boundary Condition ◽  
Dielectric Constant ◽  
Seebeck Coefficient ◽  
Gas Phase ◽  
Present Method ◽  
Dielectric Constants ◽  
Semiconductor Materials ◽  
Electronic Polarizability ◽  
Seebeck Coefficients ◽  
Good Agreement

Dielectric constants and Seebeck coefficients for semiconductor materials are studied by thermodynamic method plus ab initio quantum density functional theory (DFT). A single molecule which is formed in semiconductor material is treated in gas phase with molecular boundary condition and then electronic polarizability is directly calculated through Mulliken and atomic polar tensor (APT) density charges in the presence of the external electric field. This electronic polarizability can be converted to dielectric constant for solid material through the Clausius–Mossotti formula. Seebeck coefficient is first simulated in gas phase by thermodynamic method and then its value divided by its dielectric constant is regarded as Seebeck coefficient for solid materials. Furthermore, unit cell of semiconductor material is calculated with periodic boundary condition and its solid structure properties such as lattice constant and band gap are obtained. In this way, proper DFT function and basis set are selected to simulate electronic polarizability directly and Seebeck coefficient through chemical potential. Three semiconductor materials Mg 2 Si , β- FeSi 2 and SiGe are extensively tested by DFT method with B3LYP, BLYP and M05 functionals, and dielectric constants simulated by the present method are in good agreement with experimental values. Seebeck coefficients simulated by the present method are in reasonable good agreement with experiments and temperature dependence of Seebeck coefficients basically follows experimental results as well. The present method works much better than the conventional energy band structure theory for Seebeck coefficients of three semiconductors mentioned above. Simulation with periodic boundary condition can be generalized directly to treat with doped semiconductor in near future.

The transmission of polar effects. Part VII. A proton magnetic resonance spectra study of substituted mesitylenes, durenes, anthracenes, and triptycenes

1968 ◽  
Vol 46 (24) ◽  
pp. 3903-3908 ◽  
Author(s):  
Keith Bowden ◽  
J. G. Irving ◽  
M. J. Price
Keyword(s):  
Dielectric Constant ◽  
Free Energy ◽  
Carbon Tetrachloride ◽  
Field Effect ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Linear Free Energy ◽  
Solvent Dependence ◽  
Similar Dependence ◽  
Energy Relations

The chemical shifts of the ring protons in a series of monosubstituted mesitylenes and durenes, and of the 10-protons of a series of 9-substituted triptycenes and anthracenes have been measured in dimethyl sulfoxide, acetone, 2-methoxyethanol, and carbon tetrachloride. The solvent dependence of the substituent chemical shifts has been analyzed by linear free energy relations. The systems all show similar dependence which increases with increasing dielectric constant of the solvent. This does not result from the field effect being transmitted through the medium, but appears to arise from the formation of a hydrogen-bonded interaction between the solvent and the hydrogen of the solute. The substituent chemical shifts appear to arise from contributions from substituent field, resonance, magnetic anisotropy, and solvent effects.

scholarly journals A note on some further determinations of the dielectric constants of organic bodies and electrolytes at very low temperatures

1898 ◽  
Vol 62 (379-387) ◽  
pp. 250-266 ◽  
Keyword(s):  
Dielectric Constant ◽  
Low Temperatures ◽  
Tuning Fork ◽  
Dielectric Constants ◽  
The Past ◽  
Method Of Measurement ◽  
The Given ◽  
Past Summer

In several previous communications we have described the investigations made by us on the dielectric constants of various frozen organic bodies and electrolytes at very low temperatures. In these researches we employed a method for the measurement of the dielectric constant which consisted in charging and discharging a condenser, having the given body as dielectric, through a galvanometer 120 times in a second by means of a tuning-fork interrupter. During the past summer we have repeated some of these determinations and used a different method of measurement and a rather higher frequency. In the experiments here described we have adopted Nernst’s method for the measurement of dielectric constants, using for this purpose the apparatus as arranged by Dr. Nernst which belongs to the Davy-Faraday Laboratory.

Epitaxial Growth and Anisotropic Dielectric Properties of La-Doped Bi4Ti3O12 Thin Films

2007 ◽  
Vol 124-126 ◽  
pp. 177-180
Author(s):  
Jang Sik Lee ◽  
Q.X. Jia
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bottom Electrode ◽  
Dielectric Constants ◽  
The Other ◽  
Field Range ◽  
Anisotropic Dielectric ◽  
Dielectric Nonlinearity ◽  
La Doped

To investigate the anisotropic dielectric properties of layer-structured bismuth-based ferroelectrics along different crystal directions, we fabricate devices along different crystal orientations using highly c-axis oriented Bi3.25La0.75Ti3O12 (BLT) thin films on (001) LaAlO3 (LAO) substrates. Experimental results have shown that the dielectric properties of the BLT films are highly anisotropic along different crystal directions. The dielectric constants (1MHz at 300 K) are 358 and 160 along [100] and [110], respectively. Dielectric nonlinearity is also detected along these crystal directions. On the other hand, a much smaller dielectric constant and no detectable dielectric nonlinearity in a field range of 0-200 kV/cm are observed for films along [001] when c-axis oriented SRO is used as the bottom electrode.

Fabrication of low dielectric constant polyimide/TiO2 nanofibers with enhanced UV-light shielding properties

2018 ◽  
Vol 31 (8) ◽  
pp. 986-995
Author(s):  
Lei Wang ◽  
Guifen Gong ◽  
Junyao Shen ◽  
Jinsong Leng
Keyword(s):  
Dielectric Constant ◽  
Light Absorption ◽  
Composite Nanofibers ◽  
Uv Light ◽  
Dielectric Constants ◽  
Low Dielectric Constant ◽  
Number Density ◽  
Tio2 Nanofibers ◽  
Low Dielectric ◽  
Mechanical Tensile

Polyimide (PI)/titanium dioxide (TiO2) composite nanofibers (NFs) with average diameters of 200–250 nm were synthesized via electrospinning. The total number density of dipoles decreased significantly, owing to the porous structures and compact interface between TiO2 NPs and PI matrix. All PI/TiO2 NFs maintain low dielectric constants and losses. For example, the dielectric constants of PI/TiO2-6% NFs are all lower than 2.6, being exposed to temperatures from 25°C to 200°C. Meantime, the dielectric losses of PI/TiO2-6% NFs are below 0.005. For ultraviolet (UV)-light shielding performance, the PI/TiO2 NFs exhibited good UV-light shielding and corresponding anti-photoaging properties. The reason can be ascribed from high UV-light absorption and scattering ability in the TiO2 NPs. The best UV-light absorption (average: 3.71) and corresponding absorption decay (15.13%) were achieved for optimized PI/TiO2-6% NFs. Other fundamental characteristics, such as the thermal stability, mechanical tensile property, and hydrophobicity, were also investigated. Such low dielectric constant PI/TiO2 composite NFs can be alternatively chosen under a longtime UV-light exposing condition.

A Reusable 3D Printed Cavity Resonator for Liquid Sample Characterization

2018 ◽  
Vol 2018 (1) ◽  
pp. 000389-000392
Author(s):  
Saranraj Karuppuswami ◽  
Saikat Mondal ◽  
Mohd Ifwat Mohd Ghazali ◽  
Premjeet Chahal
Keyword(s):  
Dielectric Constant ◽  
Cavity Resonator ◽  
Dielectric Constants ◽  
Sample Holder ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
Sample Characterization ◽  
3D Printed ◽  
Standard Values ◽  
High Dielectric

Abstract In this paper, additive manufacturing (3D printing) is used to fabricate and demonstrate a reusable microfluidic coupled rectangular cavity resonator for characterizing liquids in small volumes. The designed cavity operates in the fundamental TE101 mode and resonates at 4.12 GHz. The resonance of the cavity is perturbed by the sample placed in a small volume sample holder through a slot in the top cover. Two different perturbation configurations are investigated: i) strongly coupled (liquids with low to medium dielectric constants), and ii) weakly coupled (liquids with medium to high dielectric constant). The sample holder is loaded with different solvents and the shift in the resonance frequency is monitored. Based on these changes, the dielectric constant of the solvent is theoretically estimated and compared to standard values. The reusable liquid sensor holds significant potential in identifying and quantifying unknown liquid samples in the supply chain.

Pulsed Laser Deposition of BaxSr1−xTiO3 Films on MgO, LaAlO3 and SrTiO3 for Tunable Microwave Applications

1998 ◽  
Vol 541 ◽  
Author(s):  
Wontae Chang ◽  
James S. Horwitz ◽  
Won-Jeong Kim ◽  
Jeffrey M. Pond ◽  
Steven W. Kirchoefer ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electric Field ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Dielectric Constants ◽  
Laser Deposition ◽  
Film Stress ◽  
Donor Acceptor ◽  
Bst Films

AbstractSingle phase BaxSr1−xTiO3 (BST) films (∼0.5-7 μm thick) have been deposited onto single crystal substrates (MgO, LaAlO3, SrTiO3) by pulsed laser deposition. Silver interdigitated electrodes were deposited on top of the ferroelectric film. The room temperature capacitance and dielectric Q (1/tanδ) of the film have been measured as a function of electric field (≤80 kV/cm) at 1 - 20 GHz. The dielectric properties of the film are observed to strongly depend on substrate type and post-deposition processing. After annealing (≤1000° C), it was observed that the dielectric constant and % tuning decreased and the dielectric Q increased for films deposited onto MgO, and the opposite effect was observed for films deposited onto LaA1O3. Presumably, this change in dielectric properties is due to the changes in film stress. Very thin (∼50 Å) amorphous BST films were successfully used as a stress-relief layer for the subsequently deposited crystalline BST (∼5000 Å) films to maximize % tuning and dielectric Q. Films have been deposited from stoichiometric targets and targets that have excess Ba and Sr. The additional Ba and Sr has been added to the target to compensate for deficiencies in Ba and Sr observed in the deposited BST (x=0.5) films. Films deposited from compensated targets have higher dielectric constants than films deposited from stoichiometric targets. Donor/acceptor dopants have also been added to the BST target (Mn, W, Fe ≤4 mol.%) to further improve the dielectric properties. The relationship between the dielectric constant, the dielectric Q, the change in dielectric constant with electric field is discussed.

scholarly journals On the measurement of the dielectric constants of liquids, with a determination of the dielectric constant of benzene

1929 ◽  
Vol 123 (792) ◽  
pp. 664-685 ◽  
Keyword(s):  
Dielectric Constant ◽  
Physical Properties ◽  
Dielectric Constants ◽  
Experimental Conditions ◽  
The Past ◽  
A Value ◽  
The Subject ◽  
Important Indication

It has long been recognised that the dielectric constant of a substance gives an important indication of its constitution, and the classical papers of Nernst and Drude giving methods for the determination of dielectric constants, have been followed by a long series of papers giving the dielectric constants of several hundreds of pure liquids and solutions. Since the publication of Debye’s dipole theory in 1912, the literature of the subject has become even more voluminous than before. In surveying the mass of data one is struck by the very large discrepancies which exist in the values obtained by different observers for any one substance, and it is very difficult to decide whether they are due to the difficulty of pre­paring and purifying the substance, differences in experimental conditions such as frequency of the applied E. M. F., or errors in the methods of measure­ment. In order to make it possible to compare the results of different observers, and to provide a fundamental basis for new measurements, it is important that the value of at least one standard liquid should be known with unquestion­able accuracy. The object of the present investigation was to provide such a value. Benzene was chosen as the standard liquid since it has been very widely used in the past, and it is used as a standard in the measurement of other physical properties.

Sign in / Sign up

Export Citation Format

Share Document